| Jobsite Name | City | State |
|---|---|---|
| #1 SHAFT | NANTICOKE | PA |
| #2 SHAFT | NANTICOKE | PA |
| #4 COLLIERY | JEDDO | PA |
| #4 SHAFT | DUNMORE | PA |
| #5 BREAKER | DUNMORE | PA |
| #5 SHAFT | DUNMORE | PA |
| #8 COLLIERY | DUNMORE | PA |
| 1010 RACE ST. | PHILADELPHIA | PA |
| 1709 GRAHAM AVE. | WINDBAR | PA |
| 19TH ALLEGHENY CORPORATION | PHILADELPHIA | PA |
| 2545 ARAMINGO AVE., BUILDING 30 | PHILADELPHIA | PA |
| 25TH WARD GAS WORKS | PHILADELPHIA | PA |
| 25TH WARD GAS WORKS – STATION B | PHILADELPHIA | PA |
| 2ND AVENUE PASSENGER RAILWAY | PITTSBURGH | PA |
| 3 Mile Island | Middletown | PA |
| 30TH & MARKET STREETS | PHILADELPHIA | PA |
| 3M | Bristol | PA |
| 46TH & HAVERFORD SCHOOL | PHILADELPHIA | PA |
| 5TH AND GLENWOOD AVE. | PHILADELPHIA | PA |
| 6 NORTH PROGRESS AVE. | HARRISBURG | PA |
| 600 NORTH PROGRESS ST. | HARRISBURG | PA |
| 6136 GULF | PHILADELPHIA | PA |
| 69th Street Terminal Restaurant | Philadelphia | PA |
| 7TH AVE. HOTEL | PITTSBURGH | PA |
| A – Tops Corporation | Beaver Falls | PA |
| A AND A | PHILADEPHIA | PA |
| A Hill Co | Erie | PA |
| A M BYERS COMPANY | AMBRIDGE | PA |
| A P Green | Tarentum | PA |
| A S G INDUSTRIES | JEANETTE | PA |
| A STEIERT AND SONS INC | HATFIELD | PA |
| A T & T | ALLENTOWN | PA |
| A T & T | POTTSTOWN | PA |
| A T & T | WAYNE | PA |
| A T & T CO. | READING | PA |
| A. Berg Co. | Philadelphia | PA |
| A. & P. ROBERTS COMPANY | PENCOYD | PA |
| A. & S. WILSON COMPANY | PITTSBURGH | PA |
| A. & S. WILSON COMPANY | ALLEGHENY | PA |
| A. BARLETTA & SONS | HAZELTON | PA |
| A. BLUMBERG & SONS | PHILADELPHIA | PA |
| A. Darrah Contractors | Philadelphia | PA |
| A. DERUY | SOUTH BETHLEHEM | PA |
| A. FRENCH SPRING COMPANY | PITTSBURGH | PA |
| A. GARRISON FOUNDRY COMPANY | PITTSBURGH | PA |
| A. GUCKENHEIMER & BROTHERS | FREEPORT | PA |
| A. Hirsch Air Company | Philadelphia | PA |
| A. MOE & COMPANY | PHILADELPHIA | PA |
| A. OVERHOLT & COMPANY | BROAD FORD | PA |
| A. PARDEE & COMPANY | HAZELTON | PA |
| A. WILHELM COMPANY | READING | PA |
| A.B.E. AIRPORT | ALLENTOWN | PA |
| A.C. & S. | Lancaster | PA |
| A.C. & S., INCORPORATED | PHILADELPHIA | PA |
| A.C. OVERHOLT & COMPANY | BROAD FORD | PA |
| A.E. STALEY MANUFACTURING CO. – CORN PLANT | MORRISVILLE | PA |
| A.G. Vento Plumbing Co. | Greenville | PA |
| A.H. WIRZ, INCORPORATED | CHESTER | PA |
| A.I.W. FRANK CORPORATION | EXTON | PA |
| A.J. CAMERON COMPANY | PHILADELPHIA | PA |
| A.J. HAWS & SONS LIMITED | JOHNSTOWN | PA |
| A.K. GARRETT COMPANY | PHILADELPHIA | PA |
| A.M. BYERS COMPANY | AMBRIDGE | PA |
| A.M. BYERS COMPANY | PITTSBURGH | PA |
| A.M. BYERS COMPANY, INCORPORATED | PITTSBURGH | PA |
| A.P. Green | Philadelphia | PA |
| A.P. GREEN | TARENTUM | PA |
| A.P. GREEN | TARENTUM-TARENTUM | PA |
| A.P. GREEN FIRE BRICK COMPANY | PHILADELPHIA | PA |
| A.P. GREEN FIRE BRICK COMPANY | TARENTUM | PA |
| A.P. GREEN FIRE BRICK COMPANY OF W NY | TITUSVILLE | PA |
| A.P. GREEN FIRE BRICK COMPANY, REMMEY DIVISION | PHILADELPHIA | PA |
| A.P. GREEN INDUSTRIES – REFRACTORY PLANT | PHILADELPHIA | PA |
| A.P. GREEN REFRACTORIES COMPANY | PHILADELPHIA | PA |
| A.P. GREEN SERVICES, INCORPORATED | PHILADELPHIA | PA |
| A.P. GREEN, REMMEY DIVISION | PHILADELPHIA | PA |
| A.S. SITER & SONS | MORTON | PA |
| A.T. & T. SOLID STATE TECHNOLOGY CENTER | LEIGH COUNTY | PA |
| A.T. & T. TECHNOLOGIES | ALLENTOWN | PA |
| A.W. CADMAN MANUFACTURING | PITTSBURGH | PA |
| A.Y. MICHIE | PHILADELPHIA | PA |
| ABBOTTS DAIRIES INC | BELLEVILLE | PA |
| ABBOTTS DAIRY | BELLEVILLE | PA |
| Abington High School | Abington | PA |
| Abington Hospital | Abington | PA |
| Abington School District | Abington | PA |
| ABRAMS STORAGE YARD | EAST BRIDGEPORT | PA |
| ABROQAST BASTIN COMPANY | ALLENTOWN | PA |
| Ac & S Inc. | Lancaster | PA |
| AC&S | Pittsburgh | PA |
| ACADEMY OF MUSIC – BROAD STREET | PHILADELPHIA | PA |
| Academy of the New Church | Bryn Athyn | PA |
| ACANDS, INC. | PITTSBURGH | PA |
| ACCO – Building Insulation | Lancaster | PA |
| ACE MOTOR COMPANY | PHILADELPHIA | PA |
| Acf Industries | Berwick | PA |
| ACHENBACH & BUTLER, INC. | PHILADELPHIA | PA |
| ACHENBACH & BUTLER, INC. – OFFICE BUILDING | PHILADELPHIA | PA |
| Achenbach Butler | Philadelphia | PA |
| Acme | Philadelphia | PA |
| ACME HARDESTY INDUSTRIES | PHILADELPHIA | PA |
| ACME HEAT TREAT, INC | PHILADELPHIA | PA |
| ACME IRON & METAL COMPANY | PHILADELPHIA | PA |
| ACME MARKET | NANTY GLO | PA |
| ACME MARKETS | PHILADELPHIA | PA |
| ACME MARKETS | OVERBROOK | PA |
| Acme Markets Warehouse | Reading | PA |
| ACME TEA COMPANY | PHILADELPHIA | PA |
| ACME WAREHOUSE – 30TH & OXFORD | PHILADELPHIA | PA |
| ACOUSTICRAFT, INCORPORATED, ELM AND POPLAR STS. | CONSHOHOCKEN | PA |
| ADAIRE ALEXANDER SCHOOL – EAST PALMER STREET | PHILADELPHIA | PA |
| ADAMS APPLE PRODUCTS | BENDERSVILLE | PA |
| ADAMS MINE | IRWIN | PA |
| Adelta Manufacturing | Philadelphia | PA |
| Adley Express Company | Philadelphia | PA |
| ADRIAN FURNACE | DUBOIS | PA |
| Advanced Specialty Company | Lansdale | PA |
| Aero Supply Manufacturing | Corry | PA |
| AETNA CHEMICAL COMPANY | CARNEGIE | PA |
| AETNA CHEMICAL COMPANY | OAKDALE | PA |
| AETNA EXPLOSIVE COMPANY | EMPORIUM | PA |
| AETNA EXPLOSIVES COMPANY, INCORPORATED | MT. UNION | PA |
| Aetna Standard | Ellwood City | PA |
| AGGREGATES EQUIPMENT COMPANY | LEOLA | PA |
| AIKEN MEDICAL BUILDING | PITTSBURGH | PA |
| AIR MASTER | PHILADELPHIA | PA |
| Air Production Sales | Johnstown | PA |
| AIR PRODUCTS & CHEMICALS | ALLENTOWN | PA |
| AIR PRODUCTS CO. | ALLENTOWN | PA |
| Air Products, Inc. | Emmaus | PA |
| Air Products, Inc. | Pittsburgh | PA |
| Air Reduction Plant | Bethlehem | PA |
| Air Reduction Sales Company | Bethlehem | PA |
| Air Reduction Sales Company | Butler | PA |
| Air Reduction Sales Company | Enola | PA |
| Airco | Butler | PA |
| AIRCO SPEER CARBON PRODUCTS | ST. MARYS | PA |
| Airco Speer Corporation | St. Mary | PA |
| AIRMASTER, INCORPORATED | PHILADELPHIA | PA |
| Ajax Ironworks | Corry | PA |
| AJAX METALS COMPANY | PHILADELPHIA | PA |
| ALAMOGORDO LUMBER COMPANY | SCRANTON | PA |
| ALAN WOOD IRON & STEEL COMPANY | CONSHOHOCKEN | PA |
| ALAN WOOD IRON & STEEL COMPANY | SWEDELAND | PA |
| ALAN WOOD IRON & STEEL COMPANY, STEEL DEPARTMENT | CONSHOHOCKEN | PA |
| Alan Wood Steel | Philadelphia | PA |
| ALAN WOOD STEEL | NORRISTOWN | PA |
| ALAN WOOD STEEL | CONSHOHOCKEN | PA |
| ALAN WOOD STEEL – RINER ROAD | CONSHOHOCKEN | PA |
| Alan Wood Steel Co. | Conschohocken | PA |
| Alan Wood Steel Co. | Conshohocken | PA |
| Alan Wood Steel Co. | Ivy Rock | PA |
| ALAN WOOD STEEL COMPANY | CONSHOHOCKEN | PA |
| ALAN WOOD STEEL COMPANY – BLAST FURNACE DEPT. | SWEDELAND / CONSHOSHOKEN | PA |
| ALAN WOOD STEEL, RINER RD. | CONSHOHOCKEN | PA |
| ALBERT STOVER | KINTERSVILLE | PA |
| ALBRIGHT COAL COMPANY | POTTSVILLE | PA |
| ALBRIGHT COAL COMPANY | LLEWELLYN | PA |
| ALCANIA TIN PLATE COMPANY | AVONMORE | PA |
| Alcoa | New Kensington | PA |
| Alcoa | Cressona | PA |
| Alcoa | Pittsburgh | PA |
| ALCOA | MCKEES ROCKS | PA |
| Alcoa (F/K/A Reynolds Metals) | Canonsburg | PA |
| Alcoa (F/K/A Reynolds Metals) | Glassmere | PA |
| Alcoa (F/K/A Reynolds Metals) | Pittsburgh | PA |
| Alcoa Building | Pittsburgh | PA |
| Alcoa Laboratory | New Kensington | PA |
| ALCOA NEW KENSINGTON WORKS | NEW KENSINGTON | PA |
| ALCOA RESEARCH LAB | NEW KENSINGTON | PA |
| ALCOA RESEARCH LABORATORIES | NEW KENSINGTON | PA |
| ALCOA RESEARCH LABS | NEW KENSINGTON | PA |
| ALCOA RESEARCH LABS | PITTSBURGH | PA |
| ALCOA TECHNICAL CENTER | MERWIN | PA |
| ALCOA TECHNICAL CENTER | ALCOA CENTER | PA |
| Alcoa, Cressona Work | Cressona | PA |
| ALDEN COAL COMPANY | ALDEN | PA |
| ALDON RUG MILLS | LENNI | PA |
| ALEQUIPPA STEEL COMPANY | PITTSBURGH | PA |
| ALEX CROW AND SON | PHILADELPHIA | PA |
| Alexander Brothers | Philadelphia | PA |
| Alexander Good Elementary School | York | PA |
| Alexander Plumbing Company | Pittsburgh | PA |
| Algonquin Chemical Co | Hamburg | PA |
| ALGONQUIN COAL COMPANY | WILKES BARRE | PA |
| ALGONQUIN COAL COMPANY | MINERS MILLS | PA |
| Aliquippa & Southern Railroad | Aliquippa | PA |
| ALIQUIPPA HIGH SCHOOL | ALIQUIPPA | PA |
| ALIQUIPPA JUNIOR HIGH SCHOOL | ALIQUIPPA | PA |
| ALIQUIPPA STEEL COMPANY | PITTSBURGH | PA |
| Aliquippa Works | Aliquippa | PA |
| ALIQUIPPA WORKS | WOODLAWN | PA |
| ALIQUIPPA WORKS – ALIQUIPPA TRUCK STATION 103 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – NORTH MILL PIPE SHOP – TRUCK STATION #27 (274399) | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – NORTH PIPE SHOP – TRUCK STATION NUMBER 27 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – NORTH PIPE SHOP TRUCK STATION NBR | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – PIPE SHOP – TRUCK STATION NBR 27 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – PIPE SHOP – TRUCK STATION NO. 7 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – STA. 27 N. M. PIPE SHOP | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – STA. 27 N. M. PIPE SHOP – S. G. FELGAR A-52107 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – STATION #103 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – STATION 27 – NM PIPE SHOP | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – STATION 27 N. M. PIPE SHOP | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – TRACK STATION NBR 103 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – TRUCK STATION 103 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – TRUCK STATION 27 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – TRUCK STATION NBR 013 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS – TRUCK STATION NBR 103 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS SUPPLY DEPT. – TRUCK STATION #103 | ALIQUIPPA | PA |
| ALIQUIPPA WORKS TRUCK STA NBR 103 | ALIQUIPPA | PA |
| ALL STATE INSURANCE CO | TREDYFFRIN TOWNSHIP | PA |
| ALL STATE INSURANCE COMPANY OFFICE BUILDING | TREDYFFRIN TOWNSHIP | PA |
| ALLAN WOOD IRON AND STEEL COMPANY | IVY ROCK | PA |
| ALLEGHANY AIRPORT, PITTSBURGH AIRPORT | PITTSBURGH | PA |
| ALLEGHANY LUDLUM STEEL | CLAIRTON | PA |
| ALLEGHANY LUDLUM STEEL | LEECHBURG | PA |
| Alleghany Power Company | Courtney | PA |
| Allegheny Airlines Terminal | Pittsburgh | PA |
| ALLEGHENY BY-PRODUCT COKE COMPANY | GLASSPORT | PA |
| ALLEGHENY BY-PRODUCTS COMPANY | GLASSPORT | PA |
| Allegheny Chemical | Neville Island | PA |
| ALLEGHENY CITY ELECTRIC LIGHT COMPANY – POWER PLANT | ALLEGHENY | PA |
| Allegheny County Airport | West Mifflin | PA |
| ALLEGHENY COUNTY HOME | WOODVILLE | PA |
| ALLEGHENY COUNTY HOME FOR DESTITUTE | PITTSBURGH | PA |
| ALLEGHENY COUNTY INSTITUTION DISTRICT | WOODVILLE | PA |
| ALLEGHENY COUNTY POOR FARM | WOODVILLE | PA |
| ALLEGHENY COUNTY SANITARY AUTHORITY | PITTSBURGH | PA |
| ALLEGHENY COUNTY STEAM HEATING CO. – 12TH ST. HEATING PLANT | PITTSBURGH | PA |
| ALLEGHENY COUNTY STEAM HEATING CO. – DUQUESNE BUILDING 3RD FLOOR | PITTSBURGH | PA |
| Allegheny County Steam Heating Co. – Stanwix Plant | Pittsburgh | PA |
| Allegheny County Steam Heating Co. – Stanwix Plant – 3rd Floor | Pittsburgh | PA |
| Allegheny County Steam Heating Co. – Stanwix Plant – Storeroom | Pittsburgh | PA |
| ALLEGHENY COUNTY STEAM HEATING CO. – STEAM HEATING PLANT | PITTSBURGH | PA |
| Allegheny County Steam Heating Co. – Twelfth Street Heating Plant | Pittsburgh | PA |
| ALLEGHENY COUNTY WORKHOUSE | BLAWNOX | PA |
| ALLEGHENY COUNTY WORKHOUSE | CLAREMONT | PA |
| ALLEGHENY COUNTY WORKHOUSE | HOBOKEN | PA |
| ALLEGHENY COUNTY WORKHOUSE | PITTSBURGH | PA |
| ALLEGHENY ENERGY | COURTNEY | PA |
| ALLEGHENY ENERGY | KITTANNING | PA |
| ALLEGHENY ENERGY SERVICE CORPORATION, FT. MARTIN | GREENSBURG | PA |
| ALLEGHENY ENERGY SERVICE CORPORATION, RIVESVILLE | GREENSBURG | PA |
| ALLEGHENY ENERGY SERVICE CORPORATION, WILLOW ISLAND | GREENSBURG | PA |
| ALLEGHENY ENERGY SUPPLY COMPANY | COURTNEY | PA |
| ALLEGHENY ENERGY SUPPLY COMPANY | GREENSBURG | PA |
| ALLEGHENY ENERGY SUPPLY COMPANY | MASONTOWN | PA |
| ALLEGHENY ENERGY SUPPLY COMPANY | SPRINGDALE | PA |
| ALLEGHENY FURNACE | ALTOONA | PA |
| ALLEGHENY GAS COMPANY – GAS PLANT | ALLEGHENY | PA |
| Allegheny Gasket | Bethelport | PA |
| Allegheny Gasket | Library | PA |
| ALLEGHENY GENERAL HOSPITAL | PITTSBURGH | PA |
| ALLEGHENY HEATING COMPANY | ALLEGHENY | PA |
| ALLEGHENY HIGH SCHOOL | ALLEGHENY | PA |
| Allegheny Industrial Supply | Tarentum | PA |
| Allegheny Insulation Company | Millvale & Pittsburgh | PA |
| Allegheny Ludlum | BRACKENRIDGE | PA |
| ALLEGHENY LUDLUM STEEL | BRACKENRIDGE | PA |
| ALLEGHENY LUDLUM STEEL | BRECKENRIDGE | PA |
| Allegheny Ludlum Steel Co | Brackenridge | PA |
| ALLEGHENY LUDLUM STEEL CORP. | BRACKENRIDGE | PA |
| ALLEGHENY LUDLUM STEEL CORP. | WEST LEECHBURG | PA |
| ALLEGHENY LUDLUM STEEL CORP. | LEECHBURG | PA |
| ALLEGHENY LUDLUM STEEL CORP. – MOLD PREPARATORY BLDG. | BRACKENRIDGE | PA |
| ALLEGHENY LUDLUM STEEL CORPORATION | BRACKENRIDGE | PA |
| ALLEGHENY LUDLUM STEEL CORPORATION | WEST LEECHBURG | PA |
| ALLEGHENY LUDLUM STEEL CORPORATION | WASHINGTON | PA |
| ALLEGHENY PLASTICS COMPANY | CORAOPOLIS | PA |
| ALLEGHENY PLATE GLASS COMPANY | HITE | PA |
| ALLEGHENY PLATE GLASS COMPANY | GLASSMERE | PA |
| Allegheny Power Co – Hatfield Ferry Station | Masontown | PA |
| ALLEGHENY REFINING COMPANY | VERONA | PA |
| ALLEGHENY STEEL COMPANY | BRACKENRIDGE | PA |
| ALLEGHENY VALLEY HOSPITAL | NATRONA HEIGHTS | PA |
| ALLEGHENY VALLEY STREET RAILWAY COMPANY | PITTSBURGH | PA |
| ALLEGHENY VALLEY STREET RAILWAY COMPANY | TARENTUM | PA |
| ALLEGHENY VALLEY WATER COMPANY – WATER PLANT | TARENTUM | PA |
| ALLEN LAUNDRY | ALLENTOWN | PA |
| ALLEN PRODUCTS COMPANY | ALLENTOWN | PA |
| ALLEN PRODUCTS COMPANY, INCORPORATED | ALLENTOWN | PA |
| ALLEN SHERMAN HOFF CO | WYNNEWOOD | PA |
| Allen Sherman Hoff Co. | Hamburg | PA |
| ALLENTOWN | ALLENTOWN | PENNSYLVANIA |
| ALLENTOWN AND KURTZTOWN TRACTION COMPANY | ALLENTOWN | PA |
| ALLENTOWN HIGH SCHOOL | ALLENTOWN | PA |
| ALLENTOWN HOSPITAL | ALLENTOWN | PA |
| ALLENTOWN HOSPITAL – BOILER HOUSE | ALLENTOWN | PA |
| Allentown Port Cement | Evansville | PA |
| Allentown Portland Cement Company | Evansville | PA |
| ALLENTOWN PORTLAND CEMENT COMPANY | ALLENTOWN | PA |
| ALLENTOWN RAPID SERVICE ICE COMPANY | ALLENTOWN | PA |
| Allentown State Hospital | Allentown | PA |
| Allentown Water Works | Allentown | PA |
| ALLENTOWN-BETHLEHEM GAS COMPANY – GAS PLANT | ALLENTOWN | PA |
| Allenwood Steel | Phoenixville | PA |
| Allenwood Steel | Conshohocken | PA |
| Allenwood Steel | Norristown | PA |
| Allenwood Steel Co | Sweedeland | PA |
| Allied Chemical | Newell | PA |
| Allied Chemical | Marcus Hook | PA |
| Allied Chemical | Philadelphia | PA |
| ALLIED CHEMICAL – BRIDESBURG | PHILADELPHIA | PA |
| ALLIED CHEMICAL – BRIDESBURG PLANT | PHILADELPHIA | PA |
| ALLIED CHEMICAL – BRIDGE STREET | PHILADELPHIA | PA |
| ALLIED CHEMICAL & DYE CORP. | FRANKFORD | PA |
| ALLIED CHEMICAL & DYE CORP. | SUNBURY | PA |
| ALLIED CHEMICAL & DYE CORP. | PHILADELPHIA | PA |
| ALLIED CHEMICAL & DYE CORP. – BARRETT DIVISION | BETHLEHEM | PA |
| ALLIED CHEMICAL & DYE CORP. – FRANKFORD PLANT | PHILADELPHIA | PA |
| ALLIED CHEMICAL & DYE CORP. – NEW PHENOL PLANT | PHILADELPHIA | PA |
| ALLIED CHEMICAL & DYE CORP. – WAKEFIELD ST. ENTRANCE, NEW PHOENOL | PHILADELPHIA | PA |
| ALLIED CHEMICAL & DYE CORPORATION | FRANKFORD | PA |
| ALLIED CHEMICAL & DYE CORPORATION | PHILADELPHIA | PA |
| ALLIED CHEMICAL & DYE CORPORATION BARRETT DIVISION | PHILADELPHIA | PA |
| Allied Chemical Company – Frankford Plant | Philadelphia | PA |
| ALLIED CHEMICAL CORP. | NEWELL | PA |
| ALLIED CHEMICAL CORP. | SUNBURY | PA |
| ALLIED CHEMICAL CORP. – BAKER & ADAMSON PLANT | MARCUS HOOK | PA |
| Allied Chemical Corporation | Philadelphia | PA |
| ALLIED CHEMICAL CORPORATION | BETHLEHEM | PA |
| ALLIED CHEMICAL CORPORATION | BRIDESBURG | PA |
| ALLIED CHEMICAL CORPORATION | BRIDGESBURG | PA |
| ALLIED CHEMICAL CORPORATION | YOUNGSTOWN | PA |
| ALLIED MILLS, INCORPORATED | EVERSON | PA |
| ALLIED SERVICES HANDICAPPED | SCRANTON | PA |
| ALLIED SIGNAL, INCORPORATED | PHILADELPHIA | PA |
| ALLIS CHALMERS | YORK | PA |
| ALLIS CHALMERS MFG. CO. | PITTSBURGH | PA |
| ALLIS-CHALMERS MANUFACTURING COMPANY | YORK | PA |
| ALLOY MFG. COMPANY | PITTSBURGH | PA |
| ALLOY PROPELLER COMPANY, RT. 19 | ZELIENPOLE | PA |
| ALLOY ROD | HANOVER | PA |
| Alloy Rod Plant | Hanover | PA |
| Alloy Rods Company and Chemetron Corporation | Hanover | PA |
| Alloy Rods Company and Chemetron Corporation | York | PA |
| Alloy Rods Corporation | York | PA |
| Alloy Rods Corporation | Hanover | PA |
| ALLOY STEEL | SOUTHAMPTON | PA |
| Allstate Distributors Inc | Sharon | PA |
| ALON ENGINEERING CORP | PITTSBURGH | PA |
| ALON ENGINEERING, INCORPORATED | CREIGHTON | PA |
| ALPHA PORTLAND CEMENT CO | EASTON | PA |
| ALPHA PORTLAND CEMENT COMPANY | HOWELLS | PA |
| ALPHA PORTLAND CEMENT COMPANY | PITTSBURGH | PA |
| ALPHA PORTLAND CEMENT COMPANY | EASTON | PA |
| ALPHA PORTLAND CEMENT COMPANY | MARTINS CREEK | PA |
| ALPHA PORTLAND CEMENT COMPANY, MILL #4 | MARTINS CREEK | PA |
| ALPINE KNITTING MILLS | PITTSTON | PA |
| ALPINE KNITTING MILLS | PITTSTOSS | PA |
| ALTHOUSE DIVISION | GIBRALTOR | PA |
| ALTMAN STORE, LANCASTER PK. AND IVEN RD. | RADNOR | PA |
| Altoona Area School District | Altoona | PA |
| ALTOONA CAR SHOPS | ALTOONA | PA |
| ALTOONA HIGH SCHOOL | ALTOONA | PA |
| ALTOONA HOSPITAL | ALTOONA | PA |
| ALTOONA PIPE AND STEEL PLANT | ALTOONA | PA |
| Altoona Pipe And Steel Supply Co. | Altoona | PA |
| ALTOONA SCHOOL DISTRICT, ALTOONA HIGH SCHOOL | ALTOONA | PA |
| ALTOONA VOCATIONAL TECHNOLOGY HIGH SCHOOL | ALTOONA | PA |
| ALUMINUM CO OF AMERICA | CRESSONA | PA |
| ALUMINUM CO OF AMERICA | PITTSBURGH | PA |
| Aluminum Company of America | Pittsburgh | PA |
| Aluminum Company of America | Philadelphia | PA |
| ALUMINUM COMPANY OF AMERICA | LEBANON | PA |
| ALUMINUM COMPANY OF AMERICA | LOGANS FERRY | PA |
| ALUMINUM COMPANY OF AMERICA | MERWIN | PA |
| ALUMINUM COMPANY OF AMERICA | NEW KENSINGTON | PA |
| ALUMINUM COMPANY OF AMERICA | CRESSONA | PA |
| ALUMINUM COMPANY OF AMERICA | LANCASTER | PA |
| ALUMINUM COMPANY OF AMERICA (ALCOA) | SCHUYLKILL COUNTY | PA |
| ALUMINUM COMPANY OF AMERICA (ALCOA) – WAREHOUSE BLDG. #242 | NEW KENSINGTON | PA |
| ALUMINUM COMPANY OF AMERICA, ALUMINUM PLANT | ERIE | PA |
| ALUMINUM CORPORATION OF AMERICA | LANCASTER | PA |
| ALUMINUM SMELTING CORPORATION | PHILADELPHIA | PA |
| AM. DEPARTMENT | MIDDLETOWN | PA |
| AMALGAMATED SILK CORPORATION | ALLENTOWN | PA |
| AMBER REALTY COMPANY | PHILADELPHIA | PA |
| AMBRIC TESTING AND ENGINEER | PHILADELPHIA | PA |
| AMBROSE AUGUSTERFER CORPORATION | HOLLIDAYSBURG | PA |
| AMCHEM PRODUCTS INC | AMBLER | PA |
| AMERGEN ENERGY COMPANY, LLC | MIDDLETOWN | PA |
| AMERGEN ENERGY COMPANY, LLC, T.M.I. #1 | MIDDLETOWN | PA |
| AMERGEN ENERGY COMPANY, LLC, T.M.I. #2 | MIDDLETOWN | PA |
| AMERICA OLEAN TILE COMPANY | LANDALE | PA |
| American Aniline Products Company | Lockhaven | PA |
| American Asbestos | Norristown | PA |
| American Asbestos Textile Co. | Norristown | PA |
| AMERICAN AUSTIN CAR COMPANY | BUTLER | PA |
| AMERICAN AXE AND TOOL COMPANY | BEAVER FALLS | PA |
| AMERICAN AXE AND TOOL COMPANY | GLASSPORT | PA |
| American Bank | Lafayette Hill | PA |
| AMERICAN BANK NOTE COMPANY | PHILADELPHIA | PA |
| AMERICAN BANTAM CAR COMPANY | BUTLER | PA |
| AMERICAN BAPTIST PUBLICATION SOCIETY | PHILADELPHIA | PA |
| AMERICAN BRAKE SHOE COMPANY | NEW CASTLE | PA |
| AMERICAN BRAKE SHOE COMPANY, NATIONAL BEARING DIVISION | MEADVILLE | PA |
| American Bridge | Leetsdale | PA |
| American Bridge | Ambridge | PA |
| AMERICAN BRIDGE | CLAIRTON | PA |
| AMERICAN BRIDGE COMPANY | AMBRIDGE | PA |
| AMERICAN BRIDGE COMPANY | ECONOMY | PA |
| AMERICAN BRIDGE COMPANY | PHILADELPHIA | PA |
| AMERICAN BRIDGE COMPANY | PITTSBURGH | PA |
| AMERICAN BRIDGE COMPANY | PENCOYD | PA |
| AMERICAN BRIDGE DIVISION | NORTHAMPTON | PA |
| American Bridge Division of U.S. Steel | Ambridge | PA |
| American Bridge Division of U.S. Steel Corporation | Pittsburgh | PA |
| American Bridge Shipyard | Pittsburgh | PA |
| American Can | Fairless | PA |
| AMERICAN CAN CO | CHAMBERSBURG | PA |
| AMERICAN CAN CO | EATON | PA |
| American Can Company | Morrisville | PA |
| AMERICAN CAN COMPANY | PHILADELPHIA | PA |
| AMERICAN CAN COMPANY | FAIRLESS HILLS | PA |
| AMERICAN CAN COMPANY – Delaware Ave. & Palmar Street | PHILADELPHIA | PA |
| American Car & Foundry | Wilkes Barre | PA |
| American Car & Foundry Company | Berwick | PA |
| AMERICAN CAR AND FOUNDRY COMPANY | MILTON | PA |
| AMERICAN CAR AND FOUNDRY COMPANY | BERWICK | PA |
| AMERICAN CHAIN & CABLE | MONESSEN | PA |
| AMERICAN CHAIN & CABLE COMPANY | READING | PA |
| American Chain And Cable | Braddock | PA |
| AMERICAN CHAIN COMPANY | EAST YORK | PA |
| AMERICAN CIGAR COMPANY | PHILADELPHIA | PA |
| AMERICAN CLEAN TILE | LANSDALE | PA |
| AMERICAN COKE COMPANY | PITTSBURGH | PA |
| AMERICAN COKE COMPANY | LAMBERT | PA |
| American Cyanamid | Bridgeville | PA |
| AMERICAN CYANAMID CO | BRIDGEVILLE | PA |
| AMERICAN CYANAMID CO – BRIDGEVILLE PLANT | BRIDGEVILLE | PA |
| AMERICAN CYANAMID CO – PAA PLANT | BRIDGEVILLE | PA |
| American Cyanamid Co. | Bridgeville | PA |
| American Cyanamid Company | Bridgeville | PA |
| AMERICAN DREDGE | CHESTER | PA |
| AMERICAN DREDGING – FOURTH FLOOR REAR | PHILADELPHIA | PA |
| AMERICAN DREDGING COMPANY | PHILADELPHIA | PA |
| AMERICAN DYEWOOD COMPANY | CHESTER | PA |
| AMERICAN ELECTRONICS LAB | COLMAR | PA |
| AMERICAN ENGINEERING CO | PHILADELPHIA | PA |
| AMERICAN ENGINEERING COMPANY | PHILADELPHIA | PA |
| American Hardware Supply | Parkesburg | PA |
| American Industrial Contracting | Glenfield | PA |
| American Industrial Contracting | Oil City | PA |
| American Industrial Contracting | Sewickley | PA |
| AMERICAN INDUSTRIAL CONTRACTOR | ALLISON PARK | PA |
| AMERICAN INDUSTRIAL, EAST BEAVER ST. | GLENFIELD | PA |
| AMERICAN INSULATED WIRE CORPORATION | NEW FREEDOM | PA |
| American Insulator Corp. | New Freedom | PA |
| AMERICAN IRON & STEEL COMPANY | LEBANON | PA |
| AMERICAN IRON STEEL MANUFACTURING COMPANY | LEBANON | PA |
| AMERICAN IRON-STEEL MANUFACTURING COMPANY, CENTRAL WORKS | LEBANON | PA |
| AMERICAN LACE MANUFACTURING COMPANY | GERMANTOWN | PA |
| AMERICAN LEGION BUILDING – BROAD STREET | PITTSBURGH | PA |
| American Locomotive – Railway Steel | Latrobe | PA |
| American Locomotive Co. | Latrobe | PA |
| AMERICAN LOCOMOTIVE COMPANY | CHESTER | PA |
| AMERICAN LOCOMOTIVE COMPANY | ALLEGHENY | PA |
| AMERICAN MACHINE & FOUNDR | YORK | PA |
| AMERICAN MACHINE AND FOUNDR | YORK | PA |
| American Machine And Foundry Co. | York | PA |
| AMERICAN MAGNESIA AND COVERING COMPANY | WHITE MARSH JUNCTION | PA |
| AMERICAN MAGNESIA AND COVERING COMPANY | PLYMOUTH MEETING | PA |
| American Motors | Dubois | PA |
| AMERICAN OIL COMPANY | YORKTOWN | PA |
| AMERICAN OLEAN | QUAKERTOWN | PA |
| American Olean Tile | Lansdale | PA |
| AMERICAN OLEAN TILE CO, INC | LANSDALE | PA |
| AMERICAN OLEAN TILE COMPANY | QUAKERTOWN | PA |
| AMERICAN OLEAN TILE COMPANY | LANSDALE | PA |
| AMERICAN PAPER PRODUCTS COMPANY | LANCASTER | PA |
| AMERICAN PILE FABRIC COMPANY | PHILADELPHIA | PA |
| AMERICAN PIPE MANUFACTURING COMPANY | PHILADELPHIA | PA |
| AMERICAN RADIATOR & STANDARD SANITARY CORPORATION – BESSEMER BUILDING | PITTSBURGH | PA |
| AMERICAN RADIATOR & STANDARD SANITARY CORPORATION, BESSEMER BUILDING | PITTSBURGH | PA |
| AMERICAN RADIATOR AND STANDARD SANITARY CORPORATION | PITTSBURGH | PA |
| AMERICAN RAILWAY COMPANY | PHILADELPHIA | PA |
| AMERICAN RAILWAY COMPANY | TRYONE | PA |
| AMERICAN ROAD MACHINE COMPANY | KENNETT SQUARE | PA |
| AMERICAN ROLLING MILL COMPANY | BUTLER | PA |
| AMERICAN S. & W. COMPANY | ALLEGHENY | PA |
| AMERICAN S. & W. COMPANY | PITTSBURGH | PA |
| American Salvage Company | Philadelphia | PA |
| AMERICAN SCHACK CO, INC | WEXFORD | PA |
| AMERICAN SHEET & TIN PLATE COMPANY | DEMMLER | PA |
| AMERICAN SHEET & TIN PLATE COMPANY | NEW CASTLE | PA |
| AMERICAN SHEET & TIN PLATE COMPANY | NEW KENSINGTON | PA |
| AMERICAN SHEET & TIN PLATE COMPANY | PITTSBURGH | PA |
| AMERICAN SHEET & TIN PLATE COMPANY | SCOTTDALE | PA |
| AMERICAN SHEET & TIN PLATE COMPANY | VANDERGRIFT | PA |
| AMERICAN SHEET & TIN PLATE COMPANY | LEECHBURG | PA |
| AMERICAN SHEET AND TIN PLATE COMPANY | PITTSBURGH | PA |
| AMERICAN SHEET AND TIN PLATE COMPANY | MONESSEN | PA |
| AMERICAN SHEET AND TIN PLATE COMPANY | SCOTTDALE | PA |
| AMERICAN SHEET AND TIN PLATE COMPANY | DEMMLER | PA |
| AMERICAN SHEET AND TIN PLATE COMPANY, FARREEE WORKS | FARREEE | PA |
| AMERICAN SHEET STEEL COMPANY | PITTSBURGH | PA |
| AMERICAN SHEET STEEL COMPANY | LEECHBURG | PA |
| AMERICAN SHEET STEEL COMPANY | MCKEESPORT | PA |
| AMERICAN ST GOBAIN GLASS | JEANETTE | PA |
| American Standard | Trenton | PA |
| American Steel | Pittsburgh | PA |
| AMERICAN STEEL & WIRE | PITTSBURGH | PA |
| AMERICAN STEEL AND WIRE COMPANY | PITTSBURGH | PA |
| AMERICAN STEEL AND WIRE COMPANY | ALLENTOWN | PA |
| AMERICAN STEEL AND WIRE COMPANY | DONORA | PA |
| AMERICAN STEEL AND WIRE COMPANY | RANKIN | PA |
| AMERICAN STEEL AND WIRE COMPANY | BRADDOCK | PA |
| AMERICAN STEEL AND WIRE COMPANY | BEAVER FALLS | PA |
| AMERICAN STEEL HOOP COMPANY | PITTSBURGH | PA |
| AMERICAN STEEL HOOP COMPANY | ALLEGHENY | PA |
| AMERICAN STORES COMPANY, INCORPORATED | PHILADELPHIA | PA |
| American Sugar | Philadelphia | PA |
| AMERICAN SUGAR COMPANY | PHILADELPHIA | PA |
| AMERICAN TUBE AND IRON COMPANY | MIDDLETOWN | PA |
| AMERICAN TYPE FOUNDERS COMPANY | PHILADELPHIA | PA |
| AMERICAN VERICOSE CORP | LEWISTON | PA |
| American Viscose | Philadelphia | PA |
| AMERICAN VISCOSE CORP. | MARCUS HOOK | PA |
| American Viscose Corporation | Marcus Hook | PA |
| AMERICAN VISCOSE CORPORATION | MEADVILLE | PA |
| American Viscose Plant | Lewistown | PA |
| AMERICAN WARMING & VENTILATING COMPANY | PITTSBURGH | PA |
| AMERICAN WARMING & VENTILATING COMPANY | ALTOONA | PA |
| American Water Works & Electric Company | Pittsburgh | PA |
| American Welding Company | Carbondale | PA |
| AMERICAN ZINC & CHEMICAL COMPANY | BURGETTSTOWN | PA |
| AMERICAN ZINC & CHEMICAL COMPANY | LANGELOTH | PA |
| Ametek | Sellersville | PA |
| Amjohn Incorporated | Carnegie | PA |
| AMOROSO BAKERY | PHILADELPHIA | PA |
| AMP, INCORPORATED, INTERSTATE 83 | HARRISBURG | PA |
| AMP, INCORPORATED, MAIN OFFICE BUILDING, RT. 283 | DAUPHIN COUNTY | PA |
| AMPCO METALS INCORPORATED | EDDINGTON | PA |
| AMSTAR SUGAR – DELAWARE AVENUE | PHILADELPHIA | PA |
| Amstar Sugar Factory | Philadelphia | PA |
| AMTRAK SHOPS | NOT PROVIDED | PA |
| ANCHOR BREWING COMPANY | TARENTUM | PA |
| ANCHOR GLASS CONTAINER CORPORATION | CONNELLSVILLE | PA |
| Anchor Hocking Glass Corp. | Lancaster | PA |
| ANCHOR HOCKING GLASS CORPORATION | CONNELLSVILLE | PA |
| Anchor Supply Company | Carnegie | PA |
| ANITA COAL MINING COMPANY | PUNXSUTAWNEY | PA |
| ANNEX HOTEL COMPANY | PITTSBURGH | PA |
| ANSELM SCHOOL, 7446 MCCLURE AVE. | PITTSBURGH | PA |
| Anthony Compola Plumbing | Philadelphia | PA |
| ANTHRACITE BRIQUETTE COMPANY | SUNBURY | PA |
| ANTIOCH BUILDING | PITTSBURGH | PA |
| Anvil International | Columbia | PA |
| Ap Green | Philadelphia | PA |
| AP Green Refractories Division | Tarentum | PA |
| AP Green Refractories Remmey Division | Philadelphia | PA |
| APOLLO GAS COMPANY – PUMPING STATION | TEMPLETON | PA |
| APOLLO IRON & STEEL COMPANY | PITTSBURGH | PA |
| APOLLO IRON & STEEL COMPANY | APOLLO | PA |
| APOLLO IRON & STEEL COMPANY | VANDERGRIFT | PA |
| APOLLO IRON & STEEL COMPANY | TEMPLETON | PA |
| Appleby Brothers & Whittaker | Harrisburg | PA |
| APPLETON PAPERS, INCORPORATED | ROARING SPRINGS | PA |
| APPLIED ENERGY SERVICES CORPORATION | MONACA | PA |
| Aquitaine Chemical Co | Birdsboro | PA |
| AQUITAINE CHEMICAL PLANT | BIRDSBORO | PA |
| Arbogast & Bastian | Allentown | PA |
| Arbogast & Bastlan Company | Allentown | PA |
| ARBUCKLE AND COMPANY | PITTSBURGH | PA |
| ARBUCKLE, RYAN & COMPANY, INCORPORATED | PITTSBURGH | PA |
| ARCADE BUILDING | PHILADELPHIA | PA |
| ARCADE REAL ESTATE COMPANY | PHILADELPHIA | PA |
| ARCHBISHOP CARROLL HIGH SCHOOL | RADNOR | PA |
| ARCHIBALD COLLY | ARCHIBALD | PA |
| ARCHITECTURAL STEEL | PHILADELPHIA | PA |
| Arco | Philadelphia | PA |
| Arco (Atlantic Richfield Company) | Point Breeze | PA |
| Arco Atlantic Refinery | Philadelphia | PA |
| ARCO CHEMICAL | NEWTOWN | PA |
| Arco Chemical Koppers | Monaca | PA |
| Arco Oil Refinery | Philadelphia | PA |
| Arco Polymer | Monaca | PA |
| ARCO POLYMERS | MONACO | PA |
| ARCO REFINERY | PHILADELPHIA | PA |
| Arco/Atlantic Richfield | Philadelphia | PA |
| Arco/SUNOCO | Philadelphia | PA |
| ARCOS CORPORATION | PHILADELPHIA | PA |
| ARCWIRE CORPORATION | MT CARMEL | PA |
| Arden Verner Painting | Springdale | PA |
| ARGO KNITTING MILLS | SCHUYLKILL HAVEN | PA |
| ARGO MILLS | PHILADELPHIA | PA |
| Argyl Manufacturing Co | Pen Argyl | PA |
| ARGYL MANUFACTURING COMPANY PLANT | PEN ARGYL | PA |
| ARGYL MFG CO | PEN ARGYL | PA |
| ARGYL MFG CO – MIDWAY BETWEEN WINDGAP & PEN ARGYL | PEN ARGYL | PA |
| ARGYL MFG CO – MIDWAY BETWEEN WINDGAP & PEN ARGYL – RFG 1 | PEN ARGYL | PA |
| ARGYL MFG CO – PEN ARGYL | PEN ARGYL | PA |
| Armco | Pittsburgh | PA |
| ARMCO | BUTLER | PA |
| ARMCO | MIDDLETOWN | PA |
| ARMCO | AMBRIDGE | PA |
| ARMCO | ARMBRIDGE | PA |
| ARMCO ADVANCED MATERIALS CORPORATION | BUTLER | PA |
| Armco Steel | Ambridge | PA |
| Armco Steel | Sharon | PA |
| Armco Steel | Butler | PA |
| Armco Steel Corp | Butler | PA |
| ARMCO STEEL CORP | AMBRIDGE | PA |
| ARMCO STEEL CORP – BUTLER WORKS | BUTLER | PA |
| Armco Steel Corp. | Butler | PA |
| ARMCO STEEL CORP., BUTLER WORKS, MELT SHOP MASONRY, DOOR 1-R-6 | BUTLER | PA |
| ARMCO STEEL CORPORATION | BUTLER | PA |
| ARMCO STEEL CORPORATION | AMBRIDGE | PA |
| ARMCO, INCORPORATED, SPECIALTY STEEL DIVISION | BUTLER | PA |
| ARMOUR AND COMPANY | PHILADELPHIA | PA |
| Armour Leather Co. | Kaulmont | PA |
| ARMSTRONG – CORK MILL | LANCASTER | PA |
| ARMSTRONG BROTHERS TOOL COMPANY | PITTSBURGH | PA |
| ARMSTRONG CONT & SUPPLY | LANCASTER | PA |
| ARMSTRONG CONT & SUPPLY | WASHINGTON | PA |
| Armstrong Contracting & Supply | Lancaster | PA |
| Armstrong Contracting & Supply | Harrisburg | PA |
| Armstrong Contracting & Supply | Philadelphia | PA |
| Armstrong Contracting & Supply | Pittsburgh | PA |
| ARMSTRONG CONTRACTING & SUPPLY CORPORATION | LANCASTER | PA |
| ARMSTRONG CONTRACTORS & SUPPLY | LANCASTER | PA |
| Armstrong Cork | Beaver Falls | PA |
| Armstrong Cork | Lancaster | PA |
| Armstrong Cork (Armstrong World Industries) | Lancaster | PA |
| ARMSTRONG CORK AND INSULATION COMPANY | OAKDALE | PA |
| Armstrong Cork Co. (The) | Lancaster | PA |
| Armstrong Cork Company | Lancaster | PA |
| Armstrong Cork Company | Beaver Falls | PA |
| ARMSTRONG CORK COMPANY | PITTSBURGH | PA |
| ARMSTRONG CORK COMPANY | HARRISBURG | PA |
| ARMSTRONG CORK COMPANY | PHILADELPHIA | PA |
| Armstrong Cork Company – 27th Street Plant | Beaver Falls | PA |
| ARMSTRONG CORK COMPANY – BUILDING 34-E | LANCASTER | PA |
| ARMSTRONG CORK COMPANY – BUILDINGS 403-408 | LANCASTER | PA |
| ARMSTRONG CORK COMPANY – DIGESTER & LIQUOR TANK | LANCASTER | PA |
| ARMSTRONG CORK COMPANY – DILLER PLANK INCORPORATED | LANCASTER | PA |
| ARMSTRONG CORK COMPANY – INSULATION DIVISION WAREHOUSE | PITTSBURGH | PA |
| ARMSTRONG CORK COMPANY – LANCASTER FLOOR PLANT | LANCASTER | PA |
| ARMSTRONG CORK COMPANY – PITT PLANT – 24TH STREET | PITTSBURGH | PA |
| ARMSTRONG CORK COMPANY – RESEARCH & DEVELOPMENT CENTER | LANCASTER | PA |
| ARMSTRONG CORK COMPANY – STORAGE & BLENDING TANK | LANCASTER | PA |
| ARMSTRONG CORK COMPANY – TANKS & HOOD | PITTSBURGH | PA |
| ARMSTRONG CORK COMPANY PLANT | LANCASTER | PA |
| ARMSTRONG CORK COMPANY, BUILDING 34-E | LANCASTER | PA |
| ARMSTRONG CORK COMPANY, BUILDINGS 403 TO 408 | LANCASTER | PA |
| ARMSTRONG CORK COMPANY, DIGESTER & LIQUOR TANK | LANCASTER | PA |
| ARMSTRONG CORK COMPANY, DILLER PLANK, INCORPORATED | LANCASTER | PA |
| ARMSTRONG CORK COMPANY, LINOLEUM DIVISION | LANCASTER | PA |
| ARMSTRONG CORK COMPANY, PITT PLANT, 24TH ST. | PITTSBURGH | PA |
| ARMSTRONG CORK COMPANY, STORAGE & BLENDING TANK | LANCASTER | PA |
| ARMSTRONG CORK COMPANY, TANKS & HOOD | PITTSBURGH | PA |
| Armstrong Cork, R&D Center | Lancaster | PA |
| ARMSTRONG COUNTY MEMORIAL HOSPITAL | KITTANNING | PA |
| Armstrong Incorporated W.W. | Pittsburgh | PA |
| Armstrong Power Station | Reesedale | PA |
| ARMSTRONG POWER STATION | KITTANNING | PA |
| Armstrong Sanitary Wipers | Pittsburgh | PA |
| ARMSTRONG STATION | REESDALE | PA |
| Armstrong World Industries | Lancaster | PA |
| ARMSTRONG WORLD INDUSTRIES | NEW BRIGHTON | PA |
| ARMY RESERVE CENTER | CLEARFIELD | PA |
| ARNOMINK STEAM HEAT COMPANY | DREXEL HILL | PA |
| ART LOOM CORPORATION | PHILADELPHIA | PA |
| Arthur C. Mangels Ind. | Phoenixville | PA |
| ASBESTOS AND MAGNESIA MANUFACTURING COMPANY | PORT KENNEDY | PA |
| Asbestos Insulation Company | Norristown | PA |
| ASBESTOS, SHINGLE, SLATE AND SHEATHING COMPANY | AMBLER | PA |
| ASG INDUSTRIES | JEANNETTE | PA |
| ASHLAND CHEMICAL COMPANY | PITTSBURGH | PA |
| ASHLAND EMERY & CORUNDUM COMPANY | EASTON | PA |
| ASHLAND OIL & REFINERY CO. -FREEDOM REFINERY | FREEDOM | PA |
| Ashland Oil & Refining Company | Floreffe | PA |
| ASHLAND OIL INC | FREEDOM | PA |
| ASHLAND STATE HOSPITAL | ASHLAND | PA |
| ASHLEY VILLAGE – NEW MINTZER AVENUE | NEW HOLLAND | PA |
| ASPHALT PAVING & SUPPLY | NORRISTOWN | PA |
| ASPHALT PAVING COMPANY | NORRISTOWN | PA |
| Asphalt Products | Pittsburgh | PA |
| Asten Hill | Philadelphia | PA |
| Asten Hill Mfg. | Philadelphia | PA |
| AT&T | Springfield | PA |
| ATEC BLDG. | PITTSBURGH | PA |
| ATHLETIC CLUB OF THE SCHUYLKILL NAVY | PHILADELPHIA | PA |
| ATHOS STEEL MILL | PHILADELPHIA | PA |
| ATLANTA BOILING SETTING | POWDER SPRINGS | PA |
| Atlantic & Gulf Company | Philadelphia | PA |
| ATLANTIC BAKING GROUP, INCORPORATED | PITTSBURGH | PA |
| ATLANTIC CRUSHED COKE COMPANY | GREENSBURG | PA |
| ATLANTIC FLOUR MILLS | PHILADELPHIA | PA |
| ATLANTIC METALS CORPORATION | PHILADELPHIA | PA |
| ATLANTIC OIL & HEAT | WHITE HALL | PA |
| Atlantic Oil Refinery | Philadelphia | PA |
| ATLANTIC PIPE LINE CO – FORT MIFFLIN TERMINAL | PHILADELPHIA | PA |
| ATLANTIC PORT CONTRACTORS, INCORPORATED | PHILADELPHIA | PA |
| Atlantic Refinery | Philadelphia | PA |
| ATLANTIC REFINERY CO – RESEARCH & DEVELOPMENT DEPT. – LOCATION 23 | PHILADELPHIA | PA |
| Atlantic Refining | Philadelphia | PA |
| ATLANTIC REFINING CO | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – WHSE LOC NBR 1 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – CENTRAL WAREHOUSE | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – CENTRAL WAREHOUSE – EAST SIDE | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – CENTRAL WAREHOUSE – EAST SIDE – TRACK #85 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – CENTRAL WAREHOUSE LOCATION 1 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – CENTRAL WAREHOUSE LOCATION 1 – HEADQUARTERS | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – CENTRAL WAREHOUSE LOCATION 1 – SCHUYLKILL & LANIER AVES | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – CENTRAL WAREHOUSE-EAST SIDE – B & O DELIVERY – TRACK 85 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – FOURTH FLOOR REAR | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – LOCATION 1 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – NORTH GATE – HARRY YUST | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – NORTH YARD | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – NORTH YARD ASPHALT PLANT | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – PHILADELPHIA REFINERY – NORTH YARD GATE TANK 1730 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – POINT BREEZE REFINERY | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – POINT BREEZE REFINERY – NORTH YARD | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – POINT BREEZE REFINERY – NORTH YARD – 34TH ST. GATE | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – POINT BREEZE REFINERY – NORTH YARD – WAX PLANT EXP. & HEAVY FUEL ADDN | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – POINT BREEZE REFINERY – SLABBING & PACKAGING AREA – WAX PLANT EXP. | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – POINT BREEZE REFINERY – WAX PLANT EXP. & HEAVY FUEL ADD. | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – POINT BREEZE REFINERY – WAX PLANT EXP. & HEAVY FUEL ADDN | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – RESEARCH & DEVELOPMENT CENTER | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – RESEARCH & DEVELOPMENT DEPT. – LOCATION 23 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – RT. BREEZE REFINERY | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – RT. BREEZE REFINERY – NORTH YARD – 34TH. ST. GATE | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – SCHUYLKILL AND LANIER | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – TANKS NBR 1264 & 1265 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – WAX PLANT EXP. & HEAVY FUEL ADDN – POINT BREEZE REFINERY, NORTH YARD | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – WAX PLANT EXP. & HEAVY FUEL ADDN – SOUTH YARD NEAR TANK #850 | PHILADELPHIA | PA |
| ATLANTIC REFINING CO – WOLSTONS WOODS – N YD BARGE LDG LINE | PHILADELPHIA | PA |
| ATLANTIC REFINING COMPANY | PHILADELPHIA | PA |
| ATLANTIC REFINING COMPANY | CHESTER | PA |
| ATLANTIC REFINING COMPANY | POINT BREEZE | PA |
| ATLANTIC REFINING COMPANY | PITTSBURGH | PA |
| ATLANTIC REFINING COMPANY, POINT BREEZE | PHILADELPHIA | PA |
| ATLANTIC REFINING COMPANY/ARCO, PASSYUNK AVENUE AND SCHULYKILL RIVER | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD – CENTRAL WAREHOUSE | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD – CENTRAL WAREHOUSE LOCATION 1 | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD – CENTRAL WAREHOUSE LOCATION 1 – SCHUYLKILL & LANIER | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD – LOCATION I | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD – WAREHOUSE LOCATION NBR 1 | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD CO. | PHILADELPHIA/POINT BREEZE | PA |
| ATLANTIC RICHFIELD COMPANY | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD COMPANY – BARGE LOADING FACILITIES | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD COMPANY, BARGE LOADING FACILITIES | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD REFINERY | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD REFINERY – CRACKER UNIT 853 | PHILADELPHIA | PA |
| ATLANTIC RICHFIELD REFINERY – CRACKING AREA | PHILADELPHIA | PA |
| ATLAS CEMENT COMPANY | NORTHAMPTON | PA |
| Atlas Chemicals Inc | Mertztown | PA |
| ATLAS MINERAL MACHINE COMPANY | MENTZTOWN | PA |
| Atlas Mineral Products Incorporated | Mertztown | PA |
| ATLAS PORTLAND CEMENT COMPANY | NORTHAMPTON | PA |
| ATLAS POWDER CO. | REYNOLDS | PA |
| ATLAS POWDER COMPANY | REYNOLDS | PA |
| Atochem North America | Philadelphia | PA |
| Auburn Brick Company | Auburn | PA |
| AUDENRIED #4 COLL | AUDENRIED | PA |
| AUGUST WAGNER BREWERIES, INCORPORATED | PITTSBURGH | PA |
| AURORA FURNACE | WRIGHTSVILLE | PA |
| AUSCO | ST. JOSEPH | PA |
| AUTO CAR CO | ARDMORE | PA |
| Auto Car Co. | Ardmore | PA |
| AUTO STEAM EQUIPMENT COMPANY | PHILADELPHIA | PA |
| Autocar Trucks | Exton | PA |
| AVCO SPENCER DIV. | WILLIAMSPORT | PA |
| AVTEX FIBERS INC (a/k/a American Viscose) | MARCUS HOOK | PA |
| B & O RAILROAD | CONNELLSVILLE | PA |
| B F GOODRICH COMPANY | OAKS | PA |
| B F GOODRICH TIRE COMPANY | OAKES | PA |
| B N Saul Hardware Builders Supply | Appollo | PA |
| B. & W. Main Tube Plant | Beaver Falls | PA |
| B. & W. Main Tube Plant | Pittsburg | PA |
| B. R. & P. Roundhouse | Puxsatawney | PA |
| B.F. Goodrich | Oaks | PA |
| B.F. GOODRICH COMPANY | OAKS | PA |
| B.F. Refinery | Marcus Hook | PA |
| B.P. OIL COMPANY | PHILADELPHIA | PA |
| B.P. OIL COMPANY | CHESTER | PA |
| B.P. OIL CORPORATION, ALKY FEED SYSTEM, TRAINER | PHILADELPHIA | PA |
| B.P. OIL CORPORATION, MARCUS HOOK REFINERY | MARCUS HOOK | PA |
| B.V.H. HOTEL ASSOCIATES | PHILADELPHIA | PA |
| Babcock & Wilcox | West Mayfield | PA |
| Babcock & Wilcox | Beaver Falls | PA |
| Babcock & Wilcox | Laurence County | PA |
| Babcock & Wilcox | Philadelphia | PA |
| Babcock & Wilcox | Masontown | PA |
| Babcock & Wilcox | Pittsburgh | PA |
| Babcock & Wilcox | Ambridge | PA |
| Babcock & Wilcox | Koppel | PA |
| Babcock & Wilcox | Wallace Run | PA |
| BABCOCK & WILCOX | HOMER CITY | PA |
| BABCOCK & WILCOX | MIDDLETOWN | PA |
| Babcock & Wilcox Co | Ellwood City | PA |
| Babcock & Wilcox Co, Main Tube Plant | West Mayfield | PA |
| Babcock & Wilcox Company | Wallace Run Plant | PA |
| Babcock & Wilcox Company | Beaver | PA |
| Babcock & Wilcox Company | Ambridge | PA |
| Babcock & Wilcox Company | Beaver Falls | PA |
| Babcock & Wilcox Company | Koppel | PA |
| BABCOCK & WILCOX COMPANY, TUBULAR PRODUCTS DIVISION | AMBRIDGE | PA |
| BABCOCK & WILCOX COMPANY, TUBULAR PRODUCTS DIVISION | KOPPEL | PA |
| BABCOCK & WILCOX COMPANY, TUBULAR PRODUCTS DIVISION | BEAVER FALLS | PA |
| BABCOCK & WILCOX COMPANY, TUBULAR PRODUCTS DIVISION, KOPPEL WORKS | KOPPEL | PA |
| BABCOCK & WILCOX EAST WORKS | BEAVER FALLS | PA |
| BABCOCK & WILCOX KOPPEL PLANT | KOPPEL | PA |
| Babcock & Wilcox Koppel Works | Beaver Falls | PA |
| Babcock & Wilcox Main Plant | BEAVER FALLS | PA |
| Babcock & Wilcox Steel Mills | Beaver Falls | PA |
| BABCOCK & WILCOX TUBE COMPANY | BEAVER FALLS | PA |
| Babcock & Wilcox Wallace Run Plant | BEAVER | PA |
| Babcock & Wilcox, Tubular Products Division | Koppel | PA |
| Backos & Johns Lumberyard | Pitcairn | PA |
| Badenhauser | Cornwell Heights | PA |
| BADGER CORP BENZOIL PLANT 8 | CLAIRTON | PA |
| BADGER US STEEL CHEM PLT | NEVILLE ISLAND | PA |
| BADWELL CO. | HARRISBURG | PA |
| BAEDER ADAMSON & COMPANY | PHILADELPHIA | PA |
| BAILEY BANKS & BIDDLE BUILDING | PHILADELPHIA | PA |
| BAILEY HIGH SCHOOL | PITTSBURGH | PA |
| Baird Insulation Company | Chambersburg | PA |
| BAKER CARVER & MORREL | PHILADELPHIA | PA |
| BAKER CHAIN AND WAGON IRON MANUFACTURING COMPANY | WEST RUN ALLEGHENY | PA |
| BAKER CHAIN AND WAGON IRON MANUFACTURING COMPANY | ALLEGHENY | PA |
| BAKER CO J. E. | YORK | PA |
| BAKER ELEM. SCHOOL | ALTOONA | PA |
| BAKER, SMITH & COMPANY | PITTSBURGH | PA |
| BALA CYNWYD JR HIGH SCHOOL | BALA CYNWYD | PA |
| Balch Flavor Company, Inc. | Pittsburgh | PA |
| Baldt Anchor Company | Chester | PA |
| BALDT ANCHOR FORGE CO | CHESTER | PA |
| BALDT ANCHOR, CHAIN & FORGE COMPANY | CHESTER | PA |
| BALDWIN AUTOMOTIVE | ESSINGTON | PA |
| Baldwin Lima Hamilton | Chester | PA |
| Baldwin Locomotive | Philadelphia | PA |
| Baldwin Locomotive Works | Eddystone | PA |
| BALDWIN LOCOMOTIVE WORKS | PHILADELPHIA | PA |
| BALDWIN LOCOMOTIVE WORKS | BURNHAM | PA |
| Baldwin-Ehert-Hill Inc | Port Kennedy | PA |
| Baldwin-Ehert-Hill Inc | Valley Forge | PA |
| BALDWIN-LIMA-HAMILTON CORP, STANDARD STEEL WORKS DIV., STEAM PLANT #7 | BURNHAM | PA |
| BALDWIN-LIMA-HAMILTON CORP. (a/k/a Baldwin Locomotive Works) | EDDYSTONE | PA |
| BALDWIN-LIMA-HAMILTON CORPORATION | EDDYSTONE | PA |
| BALL ENGINE COMPANY | ERIE | PA |
| BALLIED CHEMICAL & DYE CORP. – ARRETT DIVISION | PHILADELPHIA | PA |
| BALTIMORE & OHIO RAILROAD CO – DIVISION SK – SECTION A | NEW CASTLE | PA |
| BALTIMORE & OHIO RAILROAD CO – DIVISION SK – SECTION C | DUBOIS | PA |
| BALTIMORE & OHIO RAILROAD CO – DIVISION SK – SECTION C, LOCO SHOPS | DUBOIS | PA |
| BALTIMORE & OHIO RAILROAD CO – SK – SECTION A | NEW CASTLE | PA |
| BALTIMORE & OHIO RAILROAD CO. | NEW CASTLE | PA |
| BALTIMORE AND OHIO RAILROAD COMPANY | CONNELLSVILLE | PA |
| BALTIMORE AND OHIO RAILROAD COMPANY | PHILADELPHIA | PA |
| BALTIMORE AND OHIO RAILROAD COMPANY | PITTSBURGH | PA |
| BALTIMORE AND OHIO RAILROAD COMPANY | GLENWOOD | PA |
| BALTIMORE AND OHIO RAILROAD COMPANY | NEW CASTLE JUNCTION | PA |
| BANGOR ELECTRIC LIGHT, HEAT AND POWER COMPANY – POWER PLANT | BANGOR | PA |
| BANK OF NORTH AMERICA | PHILADELPHIA | PA |
| BANKS MORTON | PITTSBURGH | PA |
| BARBER ASPHALT PAVING COMPANY | PHILADELPHIA | PA |
| BARD INSULATION CO – REAR 147 2ND FLR | CHAMBERSBURG | PA |
| Bargain City | Philadelphia | PA |
| BARKLEY APARTMENTS – CITY LINE AVENUE | PHILADELPHIA | PA |
| BARNES & TUCKER | CARROLLTON | PA |
| BARNES & TUCKER COAL | CARROLLTOWN | PA |
| BARNUM BREAKER | PITTSTON | PA |
| BARNUM COLLIERY | PITTSTON | PA |
| BARONE LAUNCH SERVICE | PHILADELPHIA | PA |
| Barrett Chemical | Philadelphia | PA |
| Barrett Chemical Company | Philadelphia | PA |
| BARRETT COMPANY | PHILADELPHIA | PA |
| BARRETT COMPANY | BETHLEHEM | PA |
| BARRETT COMPANY | FRANKFORD | PA |
| BARRETT DIVISION ALLIED CHEMICAL AND DYE CORPORATION | FRANKFORD | PA |
| BARRETT DIVISION ALLIED CHEMICAL AND DYE CORPORATION | PHILADELPHIA | PA |
| BARRETT MANUFACTURING COMPANY | FRANKFORD | PA |
| BARRETTS ROOFING | PHILADELPHIA | PA |
| BARRONES LAUNCH SERV INC | PHILADELPHIA | PA |
| Barry’s Home Improvements | Cherry Tree | PA |
| BART COLERAIN ELEM SCHOOL | BARTVILLE | PA |
| BARTELS BREWING COMPANY | KINGSTON | PA |
| BASIC CONSTRUCTION COMPANY, 17TH AND MARKET STS. | PHILADELPHIA | PA |
| BATH PORTLAND CEMENT COMPANY | BATH | PA |
| BATH PORTLAND CEMENT COMPANY | SANDTS EDDY | PA |
| BATH PORTLAND CEMENT COMPANY | SANDS EDDY | PA |
| Baugh Chemical | Philadelphia | PA |
| BAYAMON | CHESTER | PA |
| BAYLESS PULP & PAPER CORP | AUSTIN | PA |
| BEACON LIGHT COMPANY – CHESTER STATION POWER PLANT | CHESTER | PA |
| Bear Gap Water Company | Shamokin | PA |
| BEAR GAP WATER COMPANY – PUMPING STATION | SHAMOKIN | PA |
| BEAR VALLEY #1 BOILER HOUSE | WILLIAMSTOWN | PA |
| BEAR VALLEY SHAFT | WILLIAMSTOWN | PA |
| BEAUMONT BIRCH COMPANY | PHILADELPHIA | PA |
| Beaunit Fibers | Elizabethon | PA |
| BEAVER COAL AND COKE COMPANY | WAMPUM | PA |
| BEAVER COUNTY GERIATRIC CENTER | BEAVER | PA |
| BEAVER COUNTY HOME AND HOSPITAL | BEAVER | PA |
| BEAVER COUNTY LIGHT COMPANY – FALLSTON POWER HOUSE | FALLSTON | PA |
| BEAVER FALLS MEDICAL CENTER | BEAVER FALLS | PA |
| BEAVER HILL APARTMENTS | JENKINTOWN | PA |
| BEAVER MEADOW COLLIERY | BEAVER MEADOW | PA |
| BEAVER MEADOW COLLIERY | DRIFTON | PA |
| BEAVER VALLEY GENERAL HOSPITAL | NEW BRIGHTON | PA |
| BEAVER VALLEY MALL | MONACA | PA |
| Beaver Valley Power Station Unit | Shippingport | PA |
| BEAVER VALLEY TRACTION COMPANY | ECONOMY | PA |
| BEAVER VALLEY TRACTION COMPANY | BEAVER | PA |
| BEAVER VALLEY TRACTION COMPANY | BEAVER FALLS | PA |
| BEAVER WIRE COMPANY | BEAVER FALLS | PA |
| Bechtel Steel Plant | Martins Creek | PA |
| BECKS RUN PUMPING STATION | PITTSBURGH | PA |
| Beckwith Mach | Harrisburg | PA |
| BECKWITH MACHINERY | MURRAYSVILLE | PA |
| BEEBER JUNIOR HJIGH SCHOOL – 59TH & MALVERN STREETS | PHILADELPHIA | PA |
| BEECHWOOD INN | JENKINTOWN | PA |
| BELFONTE WORKS – BLDG N | BELLEFONTE | PA |
| BELL TELEPHONE BUILDING – SEVENTH AVENUE | PITTSBURGH | PA |
| BELL TELEPHONE BUILDING – SOUTH MAIN STREET | WILKES-BARRE | PA |
| Bell Telephone Co. | Pittsburgh | PA |
| Bell Telephone Co. | Sharpsburg | PA |
| BELLEFIELD BOILER PLANT | PITTSBURGH | PA |
| BELLEFIELD HOTEL | PITTSBURGH | PA |
| BELLEFONTE ELECTRIC COMPANY – POWER PLANT | BELLEFONTE | PA |
| BELLEFONTE GAS COMPANY – STEAM PLANT | BELLEFONTE | PA |
| BELLEVUE STRATFORD HOTEL COMPANY | PHILADELPHIA | PA |
| BELMONT OIL WORKS / BELMONT PETROLEUM REFINERY | PHILADELPHIA | PA |
| BELMONT REFINERY | POINT BREEZE | PA |
| BEMENT, MILES & COMPANY | PHILADELPHIA | PA |
| Ben Franklin Elementary School | Levittown | PA |
| Ben Franklin Hotel | Philadelphia | PA |
| Bendix Aircraft | Philadelphia | PA |
| Bendix Corporation | Wilkes Barre | PA |
| BENDIX WESTINGHOUSE COMPANY | WILMERDING | PA |
| BENJAMIN FOSTER CO | PHILADELPHIA | PA |
| BENJAMIN FOSTER COMPANY | PHILADELPHIA | PA |
| BENJAMIN FRANKLIN ELEMENTARY SCHOOL | PHILADELPHIA | PA |
| BENJAMIN FRANKLIN JUNIOR HIGH SCHOOL | NEW CASTLE | PA |
| BENJAMIN RUSH MIDDLE SCHOOL – KNIGHTS ROAD | PHILADELPHIA | PA |
| BENNETT | PENNSYLVANIA | |
| Bennett & Aspen | Philadelphia | PA |
| BENNETT STEEL, INCORPORATED | WILKES BARRE | PA |
| BENSALEM HIGH SCHOOL | BENSALEM | PA |
| BENZOL PRODUCTS COMPANY | MARCUS HOOK | PA |
| BERGNER AND ENGLE BREWING COMPANY | PHILADELPHIA | PA |
| Berillium Corporation | Temple | PA |
| BERKS COUNTY ASSOCIATION FOR THE BLIND – HAMPDEN BOULEVARD | READING | PA |
| BERKS REFINING COMPANY | POTTSTOWN | PA |
| BERKS VOCATIONAL SCHOOL | BERKS COUNTY | PA |
| BERS & COMPANY | PHILADELPHIA | PA |
| BERS AND CO INC | PHILADELPHIA | PA |
| BERS CORPORATION | PHILADELPHIA | PA |
| Berwick Forge & Fabricating | Berwick | PA |
| BERWIN WHITE COAL COMPANY | WINDBER | PA |
| BERWIND WHITE COAL MINING COMPANY | PHILADELPHIA | PA |
| BERWIND WHITE COAL MINING COMPANY | WINDBER | PA |
| BERWIND WHITE COAL MINING COMPANY | SCALP LEVEL | PA |
| BERWIND WHITE COAL MINING COMPANY | HORATIO | PA |
| BERWIND WHITE COAL MINING COMPANY | LINDSEY | PA |
| BERWIND WHITE COAL MINING COMPANY | DUBOIS | PA |
| BERWIND WHITE COAL MINING COMPANY | DUNLO | PA |
| BERWIND WHITE COAL MINING COMPANY | EUREKA | PA |
| BERWIND WHITE COAL MINING COMPANY | OSCEOLA | PA |
| BERYLLIUM CORP. | HAZELTON | PA |
| BERYLLIUM CORP. | READING | PA |
| BERYLLIUM CORPORATION | READING | PA |
| BERYLLIUM CORPORATION | TEMPLE | PA |
| BERYLLIUM CORPORATION | HAZLETON | PA |
| BERYLLIUM CORPORATION – MANUFACTURING PLANT | TEMPLE | PA |
| BESSEMER AND LAKE ERIE RAILROAD COMPANY | GREENVILLE | PA |
| BESSEMER COKE COMPANY | PITTSBURGH | PA |
| BESSEMER LIMESTONE COMPANY | WALFORD | PA |
| BESSEMER STEEL WORKS | JOHNSTOWN | PA |
| BETH SHALOM SYNAGOGUE | PITTSBURGH | PA |
| BETHAYRES COMPANY | BETHAYRES | PA |
| BETHEHEM STEEL CORPORATION | JOHNSTOWN | PA |
| Bethel Park Borough ? Sewage Treatment Plant | Bethel Park | PA |
| BETHEL SENIOR HIGH SCHOOL | PITTSBURGH | PA |
| Bethelhem Steel Corp – Steel Mill | Ellsworth | PA |
| BETHLEHEM CORNWALL | CORNWALL | PA |
| BETHLEHEM CORNWELL CORP. – LEBANON CONCENTRATOR PLANT | LEBANON | PA |
| Bethlehem Corporation | Easton | PA |
| BETHLEHEM FAIRFIELD SHIPYARD, INCORPORATED | BETHLEHEM | PA |
| Bethlehem Foundry & Machine | Bethlehem | PA |
| BETHLEHEM IRON WORKS | BETHLEHEM | PA |
| BETHLEHEM JR. SR. HIGH SCHOOL | DEEMSTON BORO | PA |
| Bethlehem Mine & Plant | Cornwall | PA |
| Bethlehem Mine & Plant | Morgantown | PA |
| BETHLEHEM MINES CORPORATION | EBENSBURG | PA |
| BETHLEHEM MINES CORPORATION | EDENSBURG | PA |
| Bethlehem Mines Corporation – Hanover Quarry | Hanover | PA |
| BETHLEHEM SILK COMPANY | BETHLEHEM | PA |
| Bethlehem Steel | Bethlehem | PA |
| Bethlehem Steel | Johnstown | PA |
| Bethlehem Steel | Ambridge | PA |
| Bethlehem Steel | Steelton | PA |
| Bethlehem Steel | Lebanon | PA |
| Bethlehem Steel | Allentown | PA |
| BETHLEHEM STEEL | HELLERTOWN | PA |
| BETHLEHEM STEEL | HELLERSTOWN | PA |
| BETHLEHEM STEEL | EBDENBURG | PA |
| BETHLEHEM STEEL | LEETSDALE | PA |
| BETHLEHEM STEEL – BETHLEHEM WORKS | BETHLEHEM | PA |
| BETHLEHEM STEEL – JOHNSTOWN WORKS | JOHNSTOWN | PA |
| BETHLEHEM STEEL – MARTIN TOWER | BETHLEHEM | PA |
| Bethlehem Steel – No. 2 Turbo, Generator | Johnstown | PA |
| BETHLEHEM STEEL – STEELTON PLANT | STEELTON | PA |
| BETHLEHEM STEEL BUILDING, EATON AND EIGHTH AVENUE | BETHLEHEM | PA |
| BETHLEHEM STEEL CO | ALLENTOWN | PA |
| BETHLEHEM STEEL CO | JOHNSTOWN | PA |
| BETHLEHEM STEEL CO | STEELTON | PA |
| BETHLEHEM STEEL CO | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – #4 SHOP WAREHOUSE – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – #4 SHOP WAREHOUSE DEPT. | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – #4 SHOP WAREHOUSE DEPT. – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – #4 SHOP/DEPT. – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – BENSOL PLANT – COKE OVEN DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – BOILER HOUSE #2 | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – CENTRAL BOILERS DEPT | STEELTON | PA |
| BETHLEHEM STEEL CO – CENTRAL BOILERS DEPT – WEST END YARD | STEELTON | PA |
| BETHLEHEM STEEL CO – COKE OVEN DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – JOHNSTOWN STEEL MILL | JOHNSTOWN | PA |
| BETHLEHEM STEEL CO – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – LEHIGH PIPE SHOP | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – NBR 1 SHOP WAREHOUSE – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – NBR 4 SHOP WAREHOUSE | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – NBR 4 SHOP WAREHOUSE – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – NBR 4 SHOP WAREHOUSE – SERVICE DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – PIPE SHOP – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – PIPE SHOP DEPARTMENT – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – PIPE SHOP DEPARTMENT – SAUCON DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL CO – TRUCK STOP 242 | JOHNSTOWN | PA |
| BETHLEHEM STEEL CO – WEST END YARDS – SUPPLY DEPARTMENT | STEELTON | PA |
| BETHLEHEM STEEL CO – WHL PLT BRICK STORAGE – STOP 242 | JOHNSTOWN | PA |
| BETHLEHEM STEEL CO -BETHLEHEM STEEL PLANT | BETHLEHEM | PA |
| Bethlehem Steel Co. | Bethlehem | PA |
| Bethlehem Steel Co. | Steelton | PA |
| Bethlehem Steel Co. | Johnstown | PA |
| Bethlehem Steel Co. | Hanover | PA |
| Bethlehem Steel Company | Bethlehem | PA |
| Bethlehem Steel Company | Steelton | PA |
| BETHLEHEM STEEL COMPANY | JOHNSTOWN | PA |
| BETHLEHEM STEEL COMPANY | EDENSBURG | PA |
| BETHLEHEM STEEL COMPANY | EBENSBURG | PA |
| BETHLEHEM STEEL COMPANY | LEBANON | PA |
| BETHLEHEM STEEL COMPANY – SAUCON PLANT | BETHLEHEM | PA |
| BETHLEHEM STEEL COMPANY – SAUCON PLANT – BOOSTER BOILER HOUSE | BETHLEHEM | PA |
| Bethlehem Steel Corp | Lebanon | PA |
| Bethlehem Steel Corp | Steelton | PA |
| Bethlehem Steel Corp | Bethlehem | PA |
| Bethlehem Steel Corp | Johnstown | PA |
| BETHLEHEM STEEL CORP | EBENSBURG | PA |
| BETHLEHEM STEEL CORP | LEETSDALE | PA |
| BETHLEHEM STEEL CORP | LEETDALE | PA |
| BETHLEHEM STEEL CORP. | BETHLEHEM | PA |
| BETHLEHEM STEEL CORP. | JOHNSTOWN | PA |
| BETHLEHEM STEEL CORP. | STEELTON | PA |
| Bethlehem Steel Corporation | Bethlehem | PA |
| Bethlehem Steel Corporation | Cornwall | PA |
| Bethlehem Steel Corporation | Indianatown Gap | PA |
| Bethlehem Steel Corporation | Joanna | PA |
| Bethlehem Steel Corporation | Steelton | PA |
| Bethlehem Steel Corporation | Johnstown | PA |
| Bethlehem Steel Corporation | Leetsdale | PA |
| BETHLEHEM STEEL CORPORATION | EASTON | PA |
| BETHLEHEM STEEL CORPORATION | SOUTH BETHELHEM | PA |
| BETHLEHEM STEEL CORPORATION | LEBANON | PA |
| BETHLEHEM STEEL CORPORATION | REDINGTON | PA |
| BETHLEHEM STEEL CORPORATION | SOUTH BETHLEHEM | PA |
| BETHLEHEM STEEL CORPORATION | DUNAGHMORE | PA |
| BETHLEHEM STEEL CORPORATION | FRANKLIN | PA |
| BETHLEHEM STEEL CORPORATION | HOMESTEAD | PA |
| BETHLEHEM STEEL CORPORATION | NEVILLE ISLAND | PA |
| Bethlehem Steel Corporation – Homer Research Labs | Bethlehem | PA |
| BETHLEHEM STEEL CORPORATION – LEHIGH DIVISION – Bethlehem Plant | BETHLEHEM | PA |
| Bethlehem Steel Corporation – Mines | Johnstown | PA |
| BETHLEHEM STEEL CORPORATION – NEW FLANGE & STRUCTURAL MILL | BETHLEHEM | PA |
| Bethlehem Steel Corporation – Steel Mill | Johnstown | PA |
| BETHLEHEM STEEL CORPORATION – STEEL MILL | Bethlehem | PA |
| BETHLEHEM STEEL CORPORATION, BETHLEHEM LUKENS PLATE PRODUCTS | COATESVILLE | PA |
| BETHLEHEM STEEL CORPORATION, FRANKLIN WORKS | JOHNSTOWN | PA |
| BETHLEHEM STEEL CORPORATION, NEW FLANGE & STRUCTURAL MILL | BETHLEHEM | PA |
| BETHLEHEM STEEL CORPORATION, PLANT, INGOT MOLD FOUNDRY | BETHLEHEM | PA |
| BETHLEHEM STEEL CORPORATION, SCHRAPNEL DEPARTMENT. NUMBER 3 | REDINGTON | PA |
| Bethlehem Steel Mill | Pittsburgh | PA |
| BETHLEHEM STEEL PLANT – INGOT MOLD FOUNDRY | BETHLEHEM | PA |
| Bethlehem Steel Research Center | Bethlehem | PA |
| BETHLEHEM STEEL SUBSIDIARY COS. – #4 SHOP WAREHOUSE – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL SUBSIDIARY COS. – PIPE SHOP – LEHIGH DIVISION | BETHLEHEM | PA |
| BETHLEHEM STEEL SUBSIDIARY COS. – TRACK 514 TRUCK STOP 173 MECH. | JOHNSTOWN | PA |
| BETTIS ATOMIC POWER LABORATORY | WEST MIFFLIN | PA |
| Betty Brackly, Lynsk | Philadelphia | PA |
| BETZ LABS | TREVOSE | PA |
| BEYER WILLIAM AND KATHLEEN | DREXEL HILL | PA |
| BF GOODRICH COMPANY | OAKS | PA |
| BICKING PAPER MILLS | DOWNINGTON | PA |
| BICKING PAPER MILLS | DOWNINGTOWN | PA |
| BICKLEY FURNACES INC | PHILADELPHIA | PA |
| BICKLEY FURNACES, INCORPORATED | PHILADELPHIA | PA |
| BICKLEY FURNANCES INC | PHILADELPHIA | PA |
| BIG RUN MILLING COMPANY | BIG RUN, JEFFERSON COUNTY | PA |
| BILC SUPER MARKET | PHILADELPHIA | PA |
| BINDER COOPERAGE | PHILADELPHIA | PA |
| BINDLEY HARDWARE COMPANY | PITTSBURGH | PA |
| BINGHAM HOUSE | PHILADELPHIA | PA |
| BINNEY & SMITH, INC (a/k/a Kepler Mills) | EASTON | PA |
| BIRD COAL COMPANY | TIRE HILL | PA |
| BIRD COLEMAN FURNACES | CORNWALL | PA |
| BIRDSBORO CORPORATION | BIRDSBORO | PA |
| BIRMINGHAM SCHOOL | BIRMINGHAM | PA |
| Bishop Tube Company | Frazer | PA |
| BISSELL AND COMPANY | PITTSBURGH | PA |
| BLACK AND GERMER | ERIE | PA |
| Black Burn Russell Co | Bedford | PA |
| BLACK LIQUOR OXIDATION SYSTEM | SPRING GROVE | PA |
| BLACK RIVER | CHESTER | PA |
| BLACKWOOD COLLIERY | BLACKWOOD | PA |
| BLACKWOOD COLLIERY | ORWIGSBURG | PA |
| BLAKELY BOROUGH MUNICIPAL ELECTRIC PLANT | BLAKELY | PA |
| BLATTS CHEMICAL LABORATORY | FEASTERVILLE | PA |
| Blaw Knox Company | Pittsburgh | PA |
| Blaw-Know Company | Pittsburgh | PA |
| BLAW-KNOX | BUTLER | PA |
| BLAW-KNOX | PITTSBURGH | PA |
| BLAW-KNOX CO | PITTSBURGH | PA |
| Blaw-Knox Company | Blawnox | PA |
| Blaw-Knox Company | Ellwood City | PA |
| BLAW-KNOX COMPANY | CORAOPOLIS | PA |
| BLAW-KNOX COMPANY | PITTSBURGH | PA |
| BLAW-KNOX COMPANY | BLAWKNOX | PA |
| BLAW-KNOX COMPANY | BLAW KNOX | PA |
| Blawnox Mill | Blawnox | PA |
| BLIND FLORAL CO | PITTSBURGH | PA |
| BLISS SILK THROWING COMPANY – JESSUP PLANT | DICKSON CITY | PA |
| BLOOMING MILL | JOHNSTOWN | PA |
| BLOOMSBURG AREA HIGH SCHOOL – RAILROAD AVENUE | BLOOMSBURG | PA |
| BLOOMSBURG HEATING COMPANY | BLOOMSBURG | PA |
| BLOSSBURG COAL MINING & RAILROAD COMPANY | ARNOT | PA |
| BLOSSOM PRODUCTS CORPORATION | ALLENTOWN | PA |
| BLUE FLAME BURNERS INC | PITTSBURGH | PA |
| BLUE RIDGE TRACTION COMPANY | DANIELSVILLE | PA |
| BLUE RIDGE WINKLER TEXTILE CO | BANGOR | PA |
| BLUMENTHAL BROS CHOC COMPANY | PHILADELPHIA | PA |
| BLUMENTHAL BROTHERS | PHILADELPHIA | PA |
| BLUMENTHAL BROTHERS CHOCO | PHILADELPHIA | PA |
| BOARD OF EDUCATION BUILDINGS | PHILADELPHIA | PA |
| BODWELL CO | HARRISBURG | PA |
| Bodwell Company | Harrisburg | PA |
| Boehm Mfg Co | Conshohocken | PA |
| BOEING COMPANY | MORTON | PA |
| BOEING COMPANY | RIDLEY PARK | PA |
| BOEING COMPANY | EDDYSTONE | PA |
| Boeing Vertol | Eddystone | PA |
| Boeing Vertol | Ridley Park | PA |
| Boeing Vertol | Morton | PA |
| BOEING VERTOL | RIDLEY TOWNSHIP | PA |
| BOEING VERTOL COMPANY | PHILADELPHIA | PA |
| BOEING VERTOL PLANT | EDDYSTONE | PA |
| BOERICKE AND TAFEL BUILDING | PHILADELPHIA | PA |
| BOGER & CRAWFORD | PHILADELPHIA | PA |
| BOGGS & BUHL | ALLEGHENY | PA |
| BOGGS & BUHL, WEST DIAMOND ST. AND ALLEY SEMPLE MEP. CANTILE BUILDING | ALLEGHENY CITY | PA |
| Boiler Engineer & Supply Co. | Phoenixville | PA |
| BOILER ERECTION & REPAIR | AMBLER | PA |
| Boiler Service, Inc. | Spring House | PA |
| BOK TECHNICAL HIGH SCHOOL – 8TH & MIFFLIN STREETS | PHILADELPHIA | PA |
| BOLLINGER BROTHERS | PITTSBURGH | PA |
| BON SECOURS HOLY FAMILY HOSPITAL | ALTOONA | PA |
| Bonair Foundry Company | Philadelphia | PA |
| Bonded Products | West Chester | PA |
| BONNEY FORGE & TOOL WORKS | ALLENTOWN | PA |
| Bonney FRG Division | Allentown | PA |
| BORG WARNER CORPORATION | YORK | PA |
| BORNET CLEANERS | PHILADELPHIA | PA |
| BORNOT, INCORPORATED | PHILADELPHIA | PA |
| Borough of Blawnox | Blawnox | PA |
| Borough of Grove City ? Sewage Treatment Plant | Grove City | PA |
| BOROUGH OF PHOENIXVILLE | PHOENIXVILLE | PA |
| BOROUGH OF QUAKERTOWN | QUAKERTOWN | PA |
| BOROUGH OF SCHUYLKILL HAVEN | SCHUYKILL HAVEN | PA |
| BOROUGH OF TARENTUM | TARENTUM | PA |
| BORZILLO BAKERY | NORRISTOWN | PA |
| BORZILLO BAKERY INC | MORRISTOWN | PA |
| BOSTON & OHIO RAILROAD COMPANY | NEW CASTLE | PA |
| BOSTON & OHIO RAILROAD COMPANY | PITTSBURGH | PA |
| BOSTON & OHIO RAILROAD COMPANY | PHILADELPHIA | PA |
| BOSTON & OHIO RAILROAD COMPANY | GLENWOOD | PA |
| BOSTON & OHIO RAILROAD COMPANY | CONNELLSVILLE | PA |
| BOSTON IRON AND STEEL COMPANY | MCKEESPORT | PA |
| Botany 500 | Philadelphia | PA |
| BOTFIELD REFRACTORIES COMPANY, 776 S. SWANSON ST. | PHILADELPHIA | PA |
| BOTFIELD REFRACTORIES COMPANY, DIVISION O | PHILADELPHIA | PA |
| BOVAIRD & SEYFANG MFG CO – PLANT #1 | BRADFORD | PA |
| Bovaird Company | Bradford | PA |
| Bowman Trucking | Indiana | PA |
| BOYERTOWN BURIAL CASKET COMPANY | BOYERTOWN | PA |
| BOYERTOWN BURIEL CASKET | BOYERTOWN | PA |
| BP Oil | Marcus Hook | PA |
| BP OIL | PHILADELPHIA | PA |
| BP OIL | TRAINER | PA |
| BP OIL – SINCLAIR REFINERY | TRAINER | PA |
| Bp Oil Corporation | Marcus Hook | PA |
| BP OIL CORPORATION – ALKY FEED SYSTEM – TRAINER | PHILADELPHIA | PA |
| BP OIL CORPORATION – MARCUS HOOK REFINERY | MARCUS HOOK | PA |
| Bp Refinery | Chester | PA |
| BRACE COMPRESSOR STATION | BRACE | PA |
| BRACKENRIDGE WORKS SOAKING PIT | BRACKENRIDGE | PA |
| BRADDOCK GENERAL HOSPITAL | BRADDOCK | PA |
| BRADDOCK HOSPITAL – WAREHOUSE | PITTSBURGH | PA |
| BRADDOCK WIRE COMPANY | RANKIN | PA |
| BRADDOCK WIRE COMPANY | PITTSBURGH | PA |
| BRADFORD OIL REFINING | BRADFORD | PA |
| Bradford Supply Co. | Bradford | PA |
| Bradford Supply Company | Bradford | PA |
| Bradford Supply Company | Lawton Lease | PA |
| BRADLEE & COMPANY | PHILADELPHIA | PA |
| BRADSHAW AND COMPANY | PITTSBURGH | PA |
| BRAEBURN ALLOY | BRAEBURN | PA |
| BRAEBURN ALLOY | LOWER BURRELL | PA |
| BRAEBURN ALLOY STEEL COMPANY | BRAEBURN | PA |
| BRAEBURN ALLOY STEEL CORPORATION | BRAEBURN | PA |
| BRAEBURN STEEL COMPANY | BRAEBURN | PA |
| Brand Insulation | Philadelphia | PA |
| BRANDLEY SMITH | PHILADELPHIA | PA |
| BRANDYWINE MUSHROOM CO | WEST CHESTER | PA |
| BREADING PAPERBOARD CORPORATION | SINKING SPRING | PA |
| BREAKER BOILER HOUSE | GLEN LYON | PA |
| BREGY ELEMENTARY SCHOOL – 17TH & BILGER STREETS | PHILADELPHIA | PA |
| BREMAN’S EXPRESS PITTSBURGH TERMINAL | PITTSBURGH | PA |
| BRENTWOOD HIGH SCHOOL – BROWNSVILLE ROAD | PITTSBURGH | PA |
| Bressler Metal Works | Lebanon | PA |
| BRICMONT & ASSOCIATES | MCMURRAY | PA |
| BRIDGE SHOP | PENCOYD | PA |
| BRIDGEWATER PAPER COMPANY | BRIDGEWATER | PA |
| BRIER HILL COKE COMPANY | UNIONTOWN | PA |
| BRIER HILL COKE COMPANY | BRIER HILL | PA |
| Brinton Brothers | New Cumberland | PA |
| BRISTOL STEEL TREATING CO | BRISTOL | PA |
| BRISTOL WATER WORKS | BRISTOL | PA |
| BRITISH PETROLEUM COMPANY | MARCUS HOOK | PA |
| BRITISH PETROLEUM COMPANY | TRAINER | PA |
| British Petroleum Oil – Sinclair Refinery | Trainer | PA |
| British Petroleum Refinery | Marcus Hook | PA |
| British Petroleum Refinery | Trainer | PA |
| Broad Meadows Farm Delaware County Prison | Delaware County | PA |
| Brockway Glass | Clarion | PA |
| Brockway Glass | Brockway | PA |
| Brockway Glass Co | Brockway | PA |
| BROCKWAY GLASS CO., INC. | WASHINGTON | PA |
| Brockway Glass Company | Brockway | PA |
| BROCKWAY GLASS COMPANY, INCORPORATED | WASHINGTON | PA |
| BROCKWAY GLASS COMPANY, INCORPORATED | BROCKWAY | PA |
| BROMLEY LACE MILL | PHILADELPHIA | PA |
| BROOKS BROTHERS | PHILADELPHIA | PA |
| BROOKWOOD COAL COMPANY | FRACKVILLE | PA |
| BROOKWOOD COLLIERY | FRACKVILLE | PA |
| BROTHERS VALLEY COAL COMPANY | BROTHERS VALLEY TOWNSHIP | PA |
| BROUDY PRECISION EQUIPMENT | PHILADELPHIA | PA |
| BROWN AND COMPANY, INCORPORATED | PITTSBURGH | PA |
| BROWN BROTHERS & COMPANY | PHILADELPHIA | PA |
| BROWN INSTRUMENT COMPANY | PHILADELPHIA | PA |
| BROWNING, KING & COMPANY BUILDING | PHILADELPHIA | PA |
| BROWNSVILLE GOLDEN AGE NU | BROWNSVILLE | PA |
| Bruce Industrial Controls | Horsham | PA |
| BRUCE MANSFIELD POWER | SHIPPINGPORT | PA |
| BRUCE MANSFIELD POWER PLANT | Shippingport | PA |
| BRUNNER ISLAND | MIDDLETOWN | PENNSYLVANIA |
| Brunner Island Power Plant | York Haven | PA |
| BRUNNER ISLAND POWER PLANT – WESTINGHOUSE TURBINE/GENERATOR | YORK HAVEN | PA |
| BRUNOTS ISLAND | PITTSBURGH | PA |
| Brunot’s Island Powerhouse | Pittsburgh | PA |
| Brunswick Asbestos Co Inc | Philadelphia | PA |
| Brunswick Asbestos Company | Philadelphia | PA |
| Brunswick Fabricators | Philadelphia | PA |
| BRUSH ELECTRIC LIGHT COMPANY – LIGHT PLANT | PHILADELPHIA | PA |
| BRYANT SCHOOL – 60TH STREET & CEDAR AVENUE | PHILADELPHIA | PA |
| BRYDEN HORSESHOE COMPANY | CATASAUQUA | PA |
| Bryn Mawr Hospital | Bryn Mawr | PA |
| BRYTON CHEMICAL CO | CHESTER | PA |
| BRYTON CHEMICAL COMPANY | TRAINOR | PA |
| BRYTON CHEMICAL COMPANY | TRAINER | PA |
| Buchanan Lumber Co | Altoona | PA |
| Buck Hill Falls Inn | Buck Hill Falls | PA |
| BUCK IRON COMPANY | QUARRYVILLE | PA |
| BUCK IRON COMPANY INC | QUARRYVILLE | PA |
| BUCK MOUNT COLLIERY #3 | MAHANOY CITY | PA |
| BUCK RUN COAL COMPANY | MINERSVILLE | PA |
| BUCK RUN COAL COMPANY | ROHRERSVILLE | PA |
| BUCKHORN PORTLAND CEMENT COMPANY | PHILADELPHIA | PA |
| BUCKS COUNTY TECHNICAL SCHOOL – WISTAR ROAD | FAIRLESS HILLS | PA |
| BUCYRUS – ERIE | GLASSPORT | PA |
| Budd | Philadelphia | PA |
| Budd Co. | Red Lion | PA |
| Budd Company | Bridgeport | PA |
| BUDD COMPANY | PHILADELPHIA | PA |
| BUDD COMPANY | CONSHOHOCKEN | PA |
| BUDD COMPANY – RED LION PLANT | PHILADELPHIA | PA |
| BUDD COMPANY FACTORY – RED LION ROAD | PHILADELPHIA | PA |
| Budd Company, Polychem Division | Bridgeport | PA |
| BUFFALO & SUSQUEHANNA COAL & COKE COMPANY | NORTH JUNEAU | PA |
| BUFFALO & SUSQUEHANNA COAL & COKE COMPANY | SAGAMORE | PA |
| BUFFALO & SUSQUEHANNA COAL & COKE COMPANY | DUBOIS | PA |
| BUFFALO & SUSQUEHANNA COAL & COKE COMPANY | BIG RUN | PA |
| BUFFALO HARDWARE STOVE COMPANY | FREEMANS RUN | PA |
| BUFFALO VALLEY SUPPLY | LEWISBURG | PA |
| BUHL STEEL COMPANY | SHARON | PA |
| BUICK MOTOR DIVISION | PHILADELPHIA | PA |
| BUILDERS SUPPLY CO. | WILKES-BARRE | PA |
| Bulletin Building | Philadelphia | PA |
| Bundy Tubing | Coaldale | PA |
| Bundy Tubing Co. | Hometown | PA |
| BUONO BAKERY | CHESTER | PA |
| Bureau of Mines | Bruceton | PA |
| BUREAU OF MINES | PITTSBURGH | PA |
| Bureau of Mines (Dept. of Interior) | Bruceton | PA |
| BUREAU OF MINES BUILDING | PITTSBURGH | PA |
| Burke, Parsons & Bowlby | Dubois | PA |
| BURLE INDUSTRIES, INCORPORATED | LANCASTER | PA |
| BURNHAM | LANCASTER | PA |
| Burnham Boiler Company | Lancaster | PA |
| BURRELL CONSTRUCTION AND SU | NEW KENSINGTON | PA |
| BURROUGHS CORPORATION | PAULI | PA |
| BURROUGHS CORPORATION | PAOLI | PA |
| Bustleton Elementary | Philadelphia | PA |
| BUSTLETON POST OFFICE | PHILADEPHIA | PA |
| BUTLER COLLIERY | PITTSTON | PA |
| BUTLER HEALTH SYSTEM | BUTLER | PA |
| BUTLER HIGH SCHOOL | BUTLER | PA |
| BUTLER LIGHT, HEAT, AND MOTOR COMPANY – POWER PLANT | BUTLER | PA |
| BUTLER MEMORIAL HOSPITAL | BUTLER | PA |
| Butler Township | Butler | PA |
| BUTLER WORKS | BUTLER | PA |
| BYBERRY FARMS | SOMERTON | PA |
| Byberry State Hospital | Philadelphia | PA |
| Byberry State Mental Hospital | Philadelphia | PA |
| C & C AUTO PARTS | COCHRANVILLE | PA |
| C & D Battery | Conshohocken | PA |
| C & D Battery | Pennsburg | PA |
| C F REFRACTORIES | PORT KENNEDY | PA |
| C F SIMONINS AND SONS INC | PHILADELPHIA | PA |
| C H MASLAND AND SONS | CARLISLE | PA |
| C. A. REED COMPANY | WILLIAMSPORT | PA |
| C. H. Rowland | Phillipsburg | PA |
| C. HOWARD MERCY STATE HOSPITAL | PITTSBURGH | PA |
| C. Schmidt & Sons | Philadelphia | PA |
| C. SCHMIDT & SONS BREWING COMPANY | PHILADELPHIA | PA |
| C. SCHMIDT & SONS INC | PHILADELPHIA | PA |
| C.A. SPALDING | PHILADELPHIA | PA |
| C.B. COMSTOCK | PITTSBURGH | PA |
| C.C. AND E.P. TOWNSEND COMPANY | NEW BRIGHTON | PA |
| C.C. AND E.P. TOWNSEND COMPANY | FALLSTON | PA |
| C.C. HARRISON BUILDING | PHILADELPHIA | PA |
| C.C. KNIGHT AND COMPANY BUILDING | PHILADELPHIA | PA |
| C.E. MCCALL MIDDLE SCHOOL | MONTOURSVILLE | PA |
| C.E. MONDAY AND COMPANY | PHILADELPHIA | PA |
| C.F. Luppold | Leesport | PA |
| C.F. SIMONINS AND SONS | PHILADELPHIA | PA |
| C.G. HUSSEY & COMPANY | LEETSDALE | PA |
| C.H. BRADLEY AND COMPANY | PITTSBURGH | PA |
| C.H. GEIST COMPANY | PHILADELPHIA | PA |
| C.H. MASLIN AND SONS | PHILADELPHIA | PA |
| C.H. Musselman Company | Biglerville | PA |
| C.H. WHELLER MFG. CO | PHILADELPHIA | PA |
| C.L. MILLER COMPANY | SCOTTDALE | PA |
| C.R. BAIRCH AND COMPANY | EMPORIUM | PA |
| CABOT CORPORATION | SOUTH BOYERTOWN | PA |
| CALEDONIAN DYE WORKS | PHILADELPHIA | PA |
| CALLERY CHEMICAL CO. | CALLERY | PA |
| CALORIC APPLIANCE CORPORATION | TOPTON | PA |
| Caloric Corp | Topton | PA |
| CALUMET LUBRICANTS COMPANY | ROUSEVILLE | PA |
| CAMBRIA IRON COMPANY | JOHNSTOWN | PA |
| CAMBRIA LEASING CORPORATION, 73 HICKORY ST. | JOHNSTOWN | PA |
| CAMBRIA LIBRARY ASSOCIATION | JOHNSTOWN | PA |
| CAMBRIA PLANT – STEEL PLANT | JOHNSTOWN | PA |
| CAMBRIA STEEL COMPANY | JOHNSTON | PA |
| CAMBRIA STEEL COMPANY | JOHNSTOWN | PA |
| CAMBRIA STEEL COMPANY | PHILADELPHIA | PA |
| CAMBRIA STEEL COMPANY | MARIANNA | PA |
| CAMBRIA STEEL COMPANY – BEAM YARD POWER HOUSE | JOHNSTOWN | PA |
| CAMBRIA STEEL COMPANY, OFFICE BUILDING | JOHNSTOWN | PA |
| CAMDEN COPPER WORKS | PHILADELPHIA | PA |
| CAMDEN FIBRE MILLS | PHILADELPHIA | PA |
| CAMERON COLLIERY | SHAMOKIN | PA |
| Cametoo Company | Pittsburgh | PA |
| CAMPBELL SOUP CO – FOURTH FLOOR REAR | PHILADELPHIA | PA |
| CANADIAN WESTINGHOUSE LTD – WALTZ MILLS | RUFFDALE | PA |
| CANNONSBURG IRON AND STEEL COMPANY | CANONSBURG | PA |
| CANNONSBURG IRON AND STEEL COMPANY | PITTSBURGH | PA |
| CANNONSBURG STEEL AND IRON WORKS | CANONSBURG | PA |
| CANONSBURG POTTERY COMPAN | CANONSBURG | PA |
| Can-Tex Industries, Inc. | Frugality | PA |
| CAPITAL PRODUCTS | HARRISBURG | PA |
| CAPITAL PRODUCTS | MECHANICSBURG | PA |
| CAPITAL PRODUCTS COMPANY | MECHANICSBURGH | PA |
| CAPITOL PRODUCTS CO | MECHANICSBURG | PA |
| CAPITOL PRODUCTS COMPANY | MECHANICSBURG | PA |
| CAPITOL PRODUCTS COMPANY | MECHANICSVILLE | PA |
| Car Mar Welding Service | Berwick | PA |
| CARBIDE GRAPHITE GROUP, INCORPORATED | ST. MARYS | PA |
| CARBIDE GRAPHITE GROUP, INCORPORATED | SAINT MARYS | PA |
| CARBON MALLEABLE COMPANY | LANCASTER | PA |
| CARBON STEEL COMPANY | PITTSBURGH | PA |
| CARBON TRANSIT COMPANY – POWER PLANT | MAUCH CHUNK | PA |
| CARBONDALE HIGH SCHOOL | CARBONDALE | PA |
| CARBONDALE MACHINE COMPANY | CARBONDALE | PA |
| Carborundum | Latrobe | PA |
| CAREY BROTHERS WALL PAPER MANUFACTURING COMPANY | PHILADELPHIA | PA |
| Carey Manufacturing | Plymouth Meeting | PA |
| Carl P. Sheaffer Plumbing | Mechanicsburg | PA |
| CARLISLE GAS AND WATER COMPANY – WATER AND GAS PLANT | CARLISLE | PA |
| CARLISLE HOTE PRESSED WHEEL CO | NORTH MIDDLETON TOWNSHIP | PA |
| CARLSON MANUFACTURING COMPANY | CARNEGIE | PA |
| CARLSON MFG CO | CARNEGIE | PA |
| CARNEGIE BROTHERS AND COMPANY LIMITED | PITTSBURGH | PA |
| CARNEGIE ILLINOIS STEEL CORPORATION | PENCOYD | PA |
| CARNEGIE ILLINOIS STEEL CORPORATION | DRAVOSBURG | PA |
| CARNEGIE ILLINOIS STEEL CORPORATION | IRVING | PA |
| CARNEGIE ILLINOIS STEEL CORPORATION | HOMESTEAD | PA |
| CARNEGIE ILLINOIS STEEL CORPORATION | ALLEGHENY CITY | PA |
| CARNEGIE ILLINOIS STEEL CORPORATION | ETNA | PA |
| CARNEGIE ILLINOIS STEEL CORPORATION | PITTSBURGH | PA |
| CARNEGIE INSTITUTE OF TECHNOLOGY | PITTSBURGH | PA |
| CARNEGIE INSTITUTE OF TECHNOLOGY, HAMERASCHLAG HALL | PITTSBURGH | PA |
| CARNEGIE LIBRARY | MUNHALL | PA |
| CARNEGIE LIBRARY EXTENSION | PITTSBURGH | PA |
| CARNEGIE MELLON UNIVERSITY – HAMERSCHLAG HALL | PITTSBURGH | PA |
| CARNEGIE MUSEUM OF ART – SCAIFE GALLERY ADDITION | PITTSBURGH | PA |
| CARNEGIE PHIPPS AND COMPANY LIMITED | PITTSBURGH | PA |
| CARNEGIE PHIPPS AND COMPANY LIMITED | MUNHALL | PA |
| CARNEGIE SHEET COMPANY | PITTSBURGH | PA |
| Carnegie Steel | Duquesne | PA |
| CARNEGIE STEEL COMPANY | CLAIRTON | PA |
| CARNEGIE STEEL COMPANY | COCHRAN STATION | PA |
| CARNEGIE STEEL COMPANY | DUQUESNE | PA |
| CARNEGIE STEEL COMPANY | MUNHALL | PA |
| CARNEGIE STEEL COMPANY | NEW CASTLE | PA |
| CARNEGIE STEEL COMPANY | PITTSBURGH | PA |
| CARNEGIE STEEL COMPANY | RANKIN | PA |
| CARNEGIE STEEL COMPANY | SOUTH DUQUESNE | PA |
| CARNEGIE STEEL COMPANY | SHARON | PA |
| CARNEGIE STEEL COMPANY | ALLEGHENY | PA |
| CARNEGIE STEEL COMPANY | BESSEMER | PA |
| CARNEGIE STEEL COMPANY | FARRELL | PA |
| CARNEGIE STEEL COMPANY | HOMESTEAD | PA |
| CARNEGIE STEEL COMPANY | NUMHALL | PA |
| CARNEGIE STEEL COMPANY WORKS | MUNHALL | PA |
| CARNEGIE STEEL COMPANY, HOMESTEAD STEEL WORKS | MUNHALL | PA |
| CARNEGIE TECH | MCKEES ROCKS | PA |
| CARNEGIE TECHNICAL SCHOOLS | PITTSBURGH | PA |
| CARNEGIE TUBE COMPANY | CARNEGIE | PA |
| Carnegie-Illinois Steel Corp. | Rankin | PA |
| CARNEGIE-ILLINOIS STEEL CORP. (U.S. Steel) – IRVIN WORKS | IRVIN | PA |
| Carpenter Steel | Reading | PA |
| CARPENTER STEEL CO | READING | PA |
| Carpenter Steel Company | Reading | PA |
| CARPENTER TECHNOLOGY CORP | READING | PA |
| CARRIE FURNACE | IRVIN | PA |
| CARRIE FURNACE COMPANY | RANKIN | PA |
| CARRIE FURNACE COMPANY | PITTSBURGH | PA |
| CARSON INDUSTRIAL DEVELOPMENT CORPORATION | PITTSBURGH | PA |
| CARTECH CORP | READING | PA |
| CARVER ELEMENTARY SCHOOL – WEST NORRIS STREET | PHILADELPHIA | PA |
| CASANAVE SUPPLY CO. | PHILADELPHIA | PA |
| CASCADE COAL AND COKE COMPANY | TYLER | PA |
| CASCADE COAL AND COKE COMPANY | TYLER, CLEARFIELD COUNTY | PA |
| CASCADE COAL AND COKE COMPANY | SYKESVILLE | PA |
| Case Erie Supply Corp | Erie | PA |
| Cash And Carry Lumber Cco | Derry | PA |
| Castanea Paper Co. | Johnsonburg | PA |
| Catalytic Construction Company | Philadelphia | PA |
| CATALYTIC, INCORPORATED | PHILADELPHIA | PA |
| CATASAUQUA MANUFACTURING COMPANY | CATASAUQUA | PA |
| Caterpillar Corp | York | PA |
| Caterpillar Inc. | York | PA |
| Caterpillar Tractor | York | PA |
| CATERPILLAR TRACTOR CO. | EAST YORK | PA |
| CATERPILLAR TRACTOR CO. | YORK | PA |
| CATERPILLAR TRACTOR CO. – BLDG. B | EAST YORK | PA |
| CATERPILLAR TRACTOR CO. – BLDG. B | YORK | PA |
| CATERPILLAR TRACTOR CO. – BUILDING B. | YORK | PA |
| CATERPILLAR TRACTOR COMPANY – MEMORY LANCE | YORK | PA |
| CATERPILLAR TRACTOR COMPANY, MEMORY LANCE | YORK | PA |
| CEDAR CLIFF SILK COMPANY | CHAMBERSBURG | PA |
| CEDAR CREST COLLEGE | ALLENTOWN | PA |
| CEDAR STREET | NEW CASTLE | PENNSYLVANIA |
| CEDARBROOK JUNIOR HIGH SCHOOL – LONGFELLOW ROAD | WYNCOTE | PA |
| CEDERBROOK HILLS APARTMENTS | CEDERBROOK HILLS | PA |
| Celotex | Philadelphia | PA |
| Celotex Corp. | Philadelphia | PA |
| Cenco Construction Inc | Philipsburg | PA |
| CENTRAL CATHOLIC HIGH SCHOOL | ALLENTOWN | PA |
| CENTRAL CEMENT COMPANY | COPLAY | PA |
| CENTRAL DISTRICT AND PRINTING TELEGRAPH COMPANY | PITTSBURGH | PA |
| CENTRAL IRON AND STEEL COMPANY | HARRISBURG | PA |
| CENTRAL LAND COMPANY | PITTSBURGH | PA |
| CENTRAL NEW JERSEY RAILROAD | BETHLEHEM | PA |
| CENTRAL POOR DISTRICT OF LUZERNE COMPANY | WILKES BARRE | PA |
| CENTRAL POOR DISTRICT OF LUZERNE COUNTY | RETREAT | PA |
| CENTRAL RAILROAD OF NEW JERSEY | ASHLEY | PA |
| CENTRAL RAILROAD OF NEW JERSEY – ELECTRIC LIGHT PLANT | ASHLEY | PA |
| CENTRAL WORKS | LEBANON | PA |
| CENTRALIA COLLIERY | CENTRALIA | PA |
| CERTAIN TEED BOILER HOUSE | AMBLER | PA |
| Certainteed | Conshohocke | PA |
| CertainTeed | Mountaintop | PA |
| CERTAINTEED | AMBLER | PA |
| CERTAINTEED | VALLEY FORGE | PA |
| CERTAINTEED CORP. | AMBLER | PA |
| Certain-Teed Production Corporation | York | PA |
| Certainteed Products | Ambler | PA |
| CertainTeed Products Company | Philadelphia | PA |
| CERTAIN-TEED PRODUCTS CORP | YORK | PA |
| Certainteed Products Corporation | York | PA |
| CHAMBER OF COMMERCE BUILDING | PITTSBURGH | PA |
| CHAMBER REDUCTION COMPANY | E MCKEESPORT | PA |
| CHAMBER RIDGE APARTMENTS – STACY DRIVE | HARRISBURG | PA |
| Chamberlain Ammunition Depot | Scranton | PA |
| CHAMBERLAIN COAL COMPANY | POTTSVILLE | PA |
| CHAMBERLAIN COAL COMPANY | PORT CARBON | PA |
| CHAMBERLAIN CORP | SCRANTON | PA |
| CHAMBERLAIN CORPORATION | SCRATON | PA |
| CHAMBERLAIN CORPORATION | SCRANTON | PA |
| CHAMBERLAIN MANUFACTURING – SCRANTON ARMY AMMUNITION PLANT | SCRANTON | PA |
| Chamberlain Steel | Scranton | PA |
| Chambersburg Hospital | Chambersburg | PA |
| Chambersburg Market | Chambersburg | PA |
| CHAMBERSBURG POWER PLANT | CHAMBERSBURG | PA |
| Chambersburg Powerhouse | Chambersburg | PA |
| Champion Dish Washing Machine Co. | Erie | PA |
| CHAMPION VALLEY FARM – BETWEEN BERWICK & BLOOMSBURG PA | LIME RIDGE | PA |
| CHAPMAN | LEHIGH COUNTY | PA |
| CHAR. WALLACE | NEWCASTLE | PA |
| CHARLEROI BREWING COMPANY | CHARLEROI | PA |
| CHARLEROI PLATE GLASS COMPANY | PITTSBURGH | PA |
| CHARLES A. BRIGGS LUMBER AND MANUFACTURING COMPANY | SCOTTDALE | PA |
| CHARLES D. KAIER COMPANY LIMITED | MAHONEY CITY | PA |
| CHARLES E. JOHNSON AND COMPANY | PHILADELPHIA | PA |
| CHARLES E. LANGCAKE | PHILADELPHIA | PA |
| CHARLES E. MONDAY AND COMPANY | PHILADELPHIA | PA |
| CHARLES H. BOEHM HIGH SCHOOL | BUCKS COUNTY | PA |
| CHARLES H. CASPAR FOR CLASS AND NACHOD BWG. COMPANY | PHILADELPHIA | PA |
| CHARLES LACHMAN DIV (a/k/a Mohawk Carpet Mills) | PHOENIXVILLE | PA |
| CHARLES LENNIG AND COMPANY, INCORPORATED | PHILADELPHIA | PA |
| CHARLES LENNIG DIVISION OF THE ROHM & HAAS COMPANY | PHILADELPHIA | PA |
| CHARLES LENNING AND COMPANY, INCORPORATED | PHILADELPHIA | PA |
| CHARLES LENNING, TACONY CHEMICAL WORKS | PHILADELPHIA | PA |
| CHARLES MCCAUL COMPANY | PHILADELPHIA | PA |
| CHARLES ST. SUPPES | JOHNSTOWN | PA |
| CHARLES T. SCHOEN | PHILADELPHIA | PA |
| CHARMI | TUNTANNOCK | PA |
| CHARMIN PAPER | MESHOPPEN | PA |
| CHARMIN PAPER CO | MEHOOPANY | PA |
| CHARMIN PAPER CO – MECHOOPANY MILL | TUNKHANNACK | PA |
| CHARMIN PAPER COMPANY | MEHOOPANY | PA |
| CHARMIN PAPER COMPANY – OUTDOOR TANK | SCRANTON | PA |
| CHARMIN PAPER COMPANY, OUTDOOR TANK | SCRANTON | PA |
| CHARMIN PAPER PLANT | MEHOOPANY | PA |
| CHARMIN PAPER PRODS CO | KELOGPANY | PA |
| CHARMIN PAPER PRODUCTS CO | MEHOOPANY | PA |
| CHARMIN PAPER PRODUCTS CO | MEHOPANY | PA |
| CHARMIN PAPER PRODUCTS CO. | MAHOOPANY | PA |
| CHARMIN PAPER PRODUCTS COMPANY | MEHOOPANY | PA |
| CHARMIN PAPER PRODUCTS COMPANY | MEHOOPANY STATION | PA |
| CHARMIN PAPER ROD CO | MEHOOPANY | PA |
| CHARTIERS VALLEY HIGH SCHOOL | PITTSBURGH | PA |
| CHAS LACHMAN CO, INC | PHOENIXVILLE | PA |
| Chas. Pfizer & Company, Inc | Easton | PA |
| CHATFIELD AND WOODS PLANT | PITTSBURGH | PA |
| Chatham Center | Pittsburgh | PA |
| CHATHAM CENTER – WASHINGTON PLACE | PITTSBURGH | PA |
| CHATHAM COLLEGE – STUDENT FACULTY CENTER | PITTSBURGH | PA |
| Chelten Supply House | Philadelphia | PA |
| CHELTENHAM HIGH SCHOOL | CHELTENHAM | PA |
| CHELTENHAM HIGH SCHOOL | CHELTENHAM TOWNSHIP | PA |
| CHEM-CLAY CORPORATION | CARNEGIE | PA |
| CHEM-CLAY CORPORATION | PITTSBURGH | PA |
| CHEMICAL CONCENTRATES | FORT WASHINGTON | PA |
| CHEROKEE PLANT – RESEARCH BLDG – NBR 108 | DANVILLE | PA |
| CHERRY RIVER PAPER COMPANY | PHILADELPHIA | PA |
| CHERRY RIVER PAPER COMPANY, LAND TITLE BUILDING | PHILADELPHIA | PA |
| CHESTER CTY | VALLEY FORGE | PA |
| CHESTER HIGH SCHOOL | CHESTER | PA |
| CHESTER IMPROVEMENT COMPANY | THURLOW | PA |
| CHESTER LACE COMPANY | CHESTER | PA |
| CHESTER PAPER COMPANY | CHESTER | PA |
| CHESTER PROCESSING COMPANY | CHESTER | PA |
| CHESTNUT HILL ACADEMY | CHESTNUT HILL | PA |
| Chestnut Hill Hospital | Philadelphia | PA |
| CHEVRON ASPHALT CO | SPRINGDALE | PA |
| CHEW-BITTEL COMPANY | DOYLESTOWN | PA |
| CHEW-BITTEL COMPANY | WILLOW GROVE | PA |
| Chicago B & I. Bell | Scranton | PA |
| CHICAGO BRIDGE & IRON CO | GREENVILLE | PA |
| CHICAGO BRIDGE & IRON CO. | GREENVILLE | PA |
| CHICAGO BRIDGE & IRON COMPANY | GREENVILLE | PA |
| CHICAGO PNEUMATIC TOOL COMPANY | PITTSBURGH | PA |
| CHICAGO PNEUMATIC TOOL COMPANY | FRANKLIN | PA |
| CHICKIES IRON COMPANY | CHICKIES | PA |
| Childers Products | Bristol | PA |
| CHILDREN`S HOSPITAL | PHILADELPHIA | PA |
| CHILDREN`S RECEPTION WELFARE | PHILADELPHIA | PA |
| CHILDRENS HOMEOPATHIC HOSPITAL | PHILADELPHIA | PA |
| Children’s Hospital | Philadelphia | PA |
| Children’s Hospital | Pittsburgh | PA |
| CHILLED ROLL FOUNDRY | VANDERGRIFT | PA |
| CHIPMAN KNITTING COMPANY | EASTON | PA |
| CHIZ BROS CO. | MUNHALL | PA |
| CHIZ BROTHERS, INC | ELIZABETH | PA |
| CHOCURA | PHILADELPHIA | PA |
| Christ Evangelical Ref. Church | Harristown | PA |
| CHRIST M.E. CHURCH | PITTSBURGH | PA |
| CHRISTOPHER MINING COMPANY | WASHINGTON | PA |
| CHRYSLER | NEW CASTLE | PA |
| CHRYSLER | PERRYSBURG | PA |
| CHURCH OF THE HOLY SPIRIT | PALMYRA | PA |
| CHURCHVILLE ELEMENTARY | HOLLAND | PA |
| CIRCLE HEATING SERVICE | PITTSBURGH | PA |
| CITIES SERVICE OIL COMPANY | PHILADELPHIA | PA |
| Citizens Bank | Latrobe | PA |
| CITIZENS’ ELECTRIC ILLUMINATING COMPANY – LIGHT PLANT | PITTSTON | PA |
| CITIZENS ELECTRIC ILLUMINATING COMPANY – POWER PLANT | PITTSTON | PA |
| CITIZEN’S ELECTRIC LIGHT COMPANY – POWER PLANT | BRADDOCK | PA |
| CITIZENS ELECTRIC LIGHT, HEAT AND POWER COMPANY – CENTRAL STATION | MCDONALD | PA |
| CITIZENS’ ELECTRIC LIGHT, HEAT AND POWER COMPANY – POWER PLANT | LANCASTER | PA |
| CITIZENS GENERAL HOSPITAL | NEW KENSINGTON | PA |
| CITIZENS WATER COMPANY – WATER WORKS | MCDONALD | PA |
| Citizens Water Supply Co. | Washington | PA |
| City Hall & Courthouse | Easton | PA |
| CITY MILL | PHILADELPHIA | PA |
| CITY OF DANVILLE – WATER FILTRATION PLANT | DANVILLE | PA |
| CITY OF LANCASTER DEPARTMENT OF WATER – MUNICIPAL WATER WORKS | LANCASTER | PA |
| City Of Philadelphia | Philadelphia | PA |
| City of Philadelphia – Home for Indigent & House of Correction | Holmesburg | PA |
| City of Pittsburgh – 28th Street Incinerator Plant | Pittsburgh | PA |
| City of Pittsburgh – Asphalt Plant | Pittsburgh | PA |
| CITY OF PITTSBURGH BRILLIANT PUMPING STATION | PITTSBURGH | PA |
| CITY OF PITTSBURGH DEPARTMENT OF CHARITIES | MARSHALSEA | PA |
| CIVIC CENTER – 34TH STREET | PHILADELPHIA | PA |
| CLAIRE FURNACE COMPANY | SHARPSVILLE | PA |
| CLAIRTON BY-PRODUCTS COKE WORKS | CLAIRTON | PA |
| CLAIRTON HIGH SCHOOL | CLAIRTON | PA |
| CLAIRTON STEEL COMPANY | CLAIRTON | PA |
| CLAIRTON STEEL WORKS AND FURNACES | CLAIRTON | PA |
| CLAIRTON WORKS – METHYL NAPTHELINE DIVISION | CLAIRTON | PA |
| CLARION MILLS | JOHNSONBURG | PA |
| Clarion Steel Works | Pittsburgh | PA |
| CLARKS SUMMIT STATE HOSPITAL | CLARKS SUMMIT | PA |
| CLARMONT ENGINEERING | PHILADELPHIA | PA |
| CLAY ELEMENTARY SCHOOL – CLAY SCHOOL ROAD | EPHRATA | PA |
| CLAY MILL WORKS – NO .3 WORKS | CLEARFIELD | PA |
| CLEAR SPRING COAL COMPANY | PITTSTON | PA |
| CLEAR SPRING COAL COMPANY | WEST PITTSTON | PA |
| CLEARFIELD BANK | PHILADELPHIA | PA |
| CLEARFIELD HIGH SCHOOL | CLEARFIELD | PA |
| CLEARFIELD HOSPITAL | CLEARFIELD | PA |
| CLEARFIELD STEAM HEATING COMPANY – STEAM PLANT | CLEARFIELD | PA |
| CLEARVIEW ELEM. SCHOOL | BETHLEHEM | PA |
| Cleaver Brooks | Lebanon/Downingtown | PA |
| Cleaver Brooks Company | Lebanon | PA |
| CLELIAN HEIGHTS SCHOOL – CLELIAN HEIGHTS LANE | GREENSBURG | PA |
| CLERMONT ENGINEERING CO I | PHILADELPHIA | PA |
| CLEVELAND ELEMENTARY SCHOOL – NORTH NINTH STREET | ALLENTOWN | PA |
| CLEVELAND ERIE COMPANY | ELK STATION | PA |
| CLEVELAND WORSTED MILLS COMPANY | PHILADELPHIA | PA |
| CLIMAX MOLYBDENUM CO. OF PENNA. | BURGETTSTOWN | PA |
| CLIMAX MOLYBDENUM COMPANY | LANGELOTH | PA |
| CLIMAX MOLYBDENUM COMPANY | LANGELOTH / BURGETTSTOWN | PA |
| CLINTON IRON AND STEEL COMPANY | PITTSBURGH | PA |
| CLOSURE PLANT BLDG 13-D – FLR PLT BLDG 201-B | LANCASTER | PA |
| COAL AND COKE BY-PRODUCTS COMPANY | PITTSBURGH | PA |
| COAL BROOK MINE | CARBONDALE | PA |
| COAL TOWNSHIP HOUSE FOR THE ELDERLY | SHAMOKIN | PA |
| COATESVILLE ROLLING MILL COMPANY | COATESVILLE | PA |
| Cochrane D&V Crane Corp. | King of Prussia | PA |
| Codo Manufacturing Corporation | Leetsdale | PA |
| COKE | PHILADELPHIA | PA |
| COKE BOILER HOUSE | BETHLEHEM | PA |
| COKE OVEN DIVISION | BETHLEHEM | PA |
| COLFAX POWER PLANT | CHESWICK | PA |
| COLLIERIES SUPPLY AND EQUIPMENT COMPANY | PHILADELPHIA | PA |
| COLLIERY | MORRIS | PA |
| COLLIERY #18 | WANAMIE | PA |
| COLLIERY SUPPLY AND EQUIPMENT | PHILADELPHIA | PA |
| COLONIAL ALUMINUM & SMELTING CO | COLUMBIA | PA |
| COLONIAL BERKS REAL ESTATE | READING | PA |
| COLONIAL COKE COMPANY | GRINDSTONE | PA |
| COLONIAL COLLIERIES COMPANY | MINERSVILLE | PA |
| COLONIAL COLLIERIES COMPANY | MT. CARMEL | PA |
| COLONIAL IRON COMPANY | RIDDLESBURG | PA |
| COLONIAL METALS COMPANY | COLUMBIA | PA |
| COLONIAL NO. 1 PLANT | SMOCK | PA |
| Colonial Steel | MONACA | PA |
| COLONIAL STEEL COMPANY | PITTSBURGH | PA |
| COLONIAL STEEL COMPANY | MONACA | PA |
| COLONIAL STEEL COMPANY | SOUTH MONACA | PA |
| COLONIAL STEEL, DIVISION VANADIUM ALLOYS STEEL COMPANY | MONACA | PA |
| COLONIAL SUPPLY | PITTSBURGH | PA |
| COLONIAL TRUST COMPANY | READING | PA |
| Colt Industries | Midland | PA |
| COLT INDUSTRIES | PITTSBURGH | PA |
| COLT INDUSTRIES – STAINLESS STEEL & ALLOY DIV. | MIDLAND | PA |
| Colt Industries Crucible, Inc. | Midland | PA |
| COLUMBIA BOILER CO OF POT | POTTSTOWN | PA |
| COLUMBIA BRIDGE COMPANY | CARNEGIE | PA |
| COLUMBIA GAS OF PENNSYLVANIA PLANT | BEAVER FALLS | PA |
| COLUMBIA HOSPITAL | WILKINSBURG | PA |
| COLUMBIA METALS COMPANY | COLUMBIA | PA |
| Columbia Plumbing Supply House | Philadelphia | PA |
| COLUMBIA ROLLING MILL COMPANY | WATTS | PA |
| COLUMBIA ROLLING MILL COMPANY | WRIGHTSVILLE | PA |
| COLUMBIA ROLLING MILL COMPANY, VESTA FURNACE | HARRISBURG | PA |
| Columbia Water Company | Columbia | PA |
| COLUMBIAN CARBON COMPANY | PHILADELPHIA | PA |
| Comanco Inc | Berwick | PA |
| Combined Paper Mills Incorporated | Roaring Springs | PA |
| COMBUSTION ENGINEERING | MONONGAHELA | PA |
| COMBUSTION ENGINEERING – KEYSTONE STATION | ELDERTON | PA |
| COMBUSTION ENGINEERING – METROPOLITAN EDISON | READING | PA |
| Combustion Engineering Inc. | Port Kennedy | PA |
| COMBUSTION ENGINEERING, INC. | SCRANTON | PA |
| COMBUSTION ENGINEERING, INC. | PORT KENNEDY | PA |
| COMBUSTION EQUIPMENT SERV | ORELAND | PA |
| COMBUSTION EQUIPMENT SERV | QUAKERTOWN | PA |
| COMBUSTION SYSTEMS | PITTSBURGH | PA |
| Cominsky Warehouse | Windber | PA |
| COMMERCE SQUARE | PHILADELPHIA | PA |
| COMMERCE ST. BUILDING. | PHILADELPHIA | PA |
| COMMERCIAL ALCOHOL | PHILADELPHIA | PA |
| Commercial Asbestos Paper | Erie | PA |
| COMMERCIAL GAZETTE BUILDING | PITTSBURGH | PA |
| COMMONS AT FALLSINGTON | MORRISVILLE | PA |
| COMMONWEALTH OF PA | SELINSGROVE | PA |
| COMMONWEALTH OF PENNSYLVANIA – DEPARTMENT OF PUBLIC INSTRUCTION | INDIANA | PA |
| COMMONWEALTH OF PENNSYLVANIA – DEPT OF JUSTICE INS STORE ROOM | DALLAS | PA |
| COMMONWEALTH OF PENNSYLVANIA – INSTITUTION STORE ROOM DEPT – JUSTICE-STATE CORR INST – NBR 3 | BELLEFONTE | PA |
| COMMONWEALTH OF PENNSYLVANIA – LAURELTON STATE VILLAGE | LAURELTON | PA |
| COMMONWEALTH OF PENNSYLVANIA – STATE PENITENTIARY – DEPT. OF JUSTICE – PRISON SITE | GRATERFORD | PA |
| COMMONWEALTH TELEPHONE COMPANY – CENTRAL OFFICE | CLARKS SUMMIT | PA |
| COMMONWEALTH TITLE INSURANCE AND TRUST COMPANY | PHILADELPHIA | PA |
| COMMONWEALTH TRUST COMPANY | PITTSBURGH | PA |
| CON. BRAEBURN | BRAEBURN | PA |
| CONEMAUGH | NEW FLORENCE | PENNSYLVANIA |
| CONEMAUGH POWER STATION | NEW FLORENCE | PA |
| CONEMAUGH POWER STATION | WEST WHEATFIELD TOWNSHIP | PA |
| CONEMAUGH POWER STATION – UNIT #1 | NEW FLORENCE | PA |
| CONEMAUGH POWER STATION – UNIT #2 | NEW FLORENCE | PA |
| CONEMAUGH POWER STATION – UNITS #1 & #2 | NEW FLORENCE | PA |
| CONEMAUGH VALLEY MEMORIAL HOSPITAL | JOHNSTOWN | PA |
| CONESTOGA TRACTION COMPANY | LANCASTER | PA |
| CONEWANGO REFINING COMPANY | WARREN | PA |
| Congoleum | Marcus Hook | PA |
| Congoleum Co. | Marcus Hook | PA |
| CONGOLEUM COMPANY, INCORPORATED | MARCUS HOOK | PA |
| Congoleum Nairn | Marcus Hook | PA |
| CONGOLEUM PLANT | MARCUS HOOK | PA |
| CONGOLEUM-NAIRN, INCORPORATED | MARCUS HOOK | PA |
| CONNEAUT AND ERIE TRACTION COMPANY | ELK STATION | PA |
| CONNELLY CONTAINERS, INCORPORATED | BALA CYNWYD | PA |
| CONNELLY CONTAINERS, INCORPORATED | PHILADELPHIA | PA |
| CONNELLY PAPER COMPANY | PHILADELPHIA | PA |
| Conrail | Altoona | PA |
| Conrail | Reading | PA |
| CONRAIL (CONSILADATED RAILROAD) | ALTOONA | PA |
| Conrail (Consolidated Railroad) | Reading | PA |
| CONRAIL/PENN CENTRAL/NEW YORK CENTRAL/PENNSYLV | NOT PROVIDED | PA |
| CONSHOHOCKEN WORSTED MILLS COMPANY | CONSHOHOCKEN | PA |
| CONSHOHOCKEN WORSTED MILLS COMPANY | PHILADELPHIA | PA |
| Consolick Com Station | Tamarack | PA |
| CONSOLIDATED CIGAR CO. | LANCASTER | PA |
| CONSOLIDATED CIGAR CORP | CARBON | PA |
| CONSOLIDATED CIGAR CORP | MC ADOO | PA |
| CONSOLIDATED CIGAR CORPORATION | MCADOO | PA |
| CONSOLIDATED CIGAR CORPORATION / MAFCO | MCADOO | PA |
| CONSOLIDATED COAL COMPANY | LIBRARY | PA |
| CONSOLIDATED GAS COMPRESSOR STATION | DELMONT | PA |
| Consolidated Gas Supply Corporation – Sabinsville Station | SABINSVILLE | PA |
| CONSOLIDATED ICE COMPANY | PITTSBURGH | PA |
| Consolidated Rail Corp. | Philadelphia | PA |
| CONSOLIDATED RAILWAY CORPORATION | ENOLA | PA |
| CONSOLIDATED RAILWAY CORPORATION | CONWAY | PA |
| CONSOLIDATED RAILWAY CORPORATION | PHILADELPHIA | PA |
| CONSOLIDATED STEEL & WIRE COMPANY | ALLENTOWN | PA |
| CONSOLIDATED STEEL & WIRE COMPANY | PITTSBURGH | PA |
| CONSOLIDATED STEEL & WIRE COMPANY | BEAVER FALLS | PA |
| CONSOLIDATED STEEL & WIRE COMPANY | RANKIN | PA |
| CONSOLIDATED TRACTION COMPANY | PITTSBURGH | PA |
| CONSOLIDATION COAL CO – RESEARCH & DEVELOPMENT DIVISION | LIBRARY | PA |
| CONSOLIDATION COAL COMPANY | LIBRARY | PA |
| CONSOLIDATION COAL COMPANY | JENNER | PA |
| Consumers Gas Company | Reading | PA |
| CONSUMERS LIGHT COMPANY – LIGHT PLANT | PLYMOUTH | PA |
| CONSUMER’S MINING | HARMARVILLE | PA |
| Container Corporation of America | Philadelphia | PA |
| Container Corporation of America | Rencoyd | PA |
| Container Corporation of America | Manayunk | PA |
| CONTAINER DIVISION | ALDAN BOROUGH | PA |
| Continental Can | West Mifflin | PA |
| CONTINENTAL DIAMOND FIBRE / DIAMOND STATE FIBRE COMPANY | BRIDGEPORT | PA |
| Continental Distilling Company | Philadelphia | PA |
| CONTINENTAL DISTILLING CORP | Philadelphia | PA |
| CONTINENTAL DISTILLING CORP/KNABB BARREL DIV. | MARCUS HOOK | PA |
| CONTINENTAL MILLS, INCORPORATED | PHILADELPHIA | PA |
| CONTINENTAL OIL CO | CHESTER | PA |
| CONTINENTAL RUBBER WORKS | ERIE | PA |
| Continental Wire & Cable | York | PA |
| Contract Server Trucking Co. | Calmar | PA |
| CONVENT OF MERCY | PITTSBURGH | PA |
| CONVENTION CENTER | PHILADELPHIA | PA |
| COOPER HEWITT COMPANY, DURHAM IRON WORKS | RIEGELSVILLE | PA |
| COOPER INDUSTRIES | CORRY | PA |
| COPLAY CEMENT COMPANY | COPLAY | PA |
| COPLAY CEMENT MANUFACTURING | NAZARETH | PA |
| COPLAY CEMENT MANUFACTURING COMPANY | COPLAY | PA |
| COPLAY CEMENT MANUFACTURING COMPANY | ALLENTOWN | PA |
| COPLAY CEMENT MFG CO | COPLAY | PA |
| Copper Pittsburg Co | Bridgeville | PA |
| COPPER RANGE COMPANY | LEETSDALE | PA |
| Copperweld | Glassport | PA |
| CORAPOLIS ICE PLANT | CORAPOLIS | PA |
| Corbits, Inc. | Birdsboro | PA |
| CORN AND CORN COB PRODUCTS | PHILADELPHIA | PA |
| CORNELL MANUFACTURING COMPANY | LACEYVILLE | PA |
| CORNING | CHARLEROI | PA |
| CORNING | BRADFORD | PA |
| Corning Glass | Charleroi | PA |
| CORNING GLASS | BELLEFONTE | PA |
| CORNING GLASS | CHAMBERSBURG | PA |
| CORNING GLASS CO. | STATE COLLEGE | PA |
| Corning Glass Plant | Pittsburgh | PA |
| Corning Glass Works | Charleroi | PA |
| Corning Glass Works | Greencastle | PA |
| CORNING GLASS WORKS | BRADFORD | PA |
| CORNING GLASS WORKS – BRADFORD PLANT | BRADFORD | PA |
| CORNING GLASS WORKS COMPONENT PLANT | BRADFORD | PA |
| CORNWALL IRON COMPANY | CORNWALL | PA |
| CORNWALL ORE BANK COMPANY | CORNWALL | PA |
| CORONADA APARTMENTS | PITTSBURGH | PA |
| CORRIGAN-MCKENNEY STEEL COMPANY | SHARPSVILLE | PA |
| CORRIGAN-MCKENNEY STEEL COMPANY | BLACK LICK | PA |
| COUDERSPORT JUNIOR & SENIOR HIGH SC | COUDERSPORT | PA |
| Council Rock High School | Bucks County | PA |
| COUNTRY BELLE COOPERATIVE | PITTSBURGH | PA |
| Country Dry Wall | Williamsport | PA |
| COUSINS COFFEESHOP | PHILADELPHIA | PA |
| COVE | CHESTER | PA |
| COWANSHANNOCK COAL AND COKE COMPANY | PUNXSUTAWNEY | PA |
| COWANSHANNOCK COAL AND COKE COMPANY | YATESBORO | PA |
| COXE BROTHERS AND COMPANY | DERINGER | PA |
| COXE BROTHERS AND COMPANY | DRIFTON | PA |
| COXE TRAVELING GRATE COMPANY | PORT CARBON | PA |
| CRAFTON ICE COMPANY | CRAFTON | PA |
| CRAMP SCHOOL | PHILADELPHIA | PA |
| Cramp Shipbuilding | Philadelphia | PA |
| Cramp Shipyard | Philadelphia | PA |
| Cramps Shipbuilding Co. | Philadelphia | PA |
| CRAMPS SHIPYARD | PHILADELPHIA | PA |
| Cramps Shipyard – Offices | Philadelphia | PA |
| CRAMPSHIPYARD DRAVO CORPORATION | PHILADELPHIA | PA |
| CRANE COMPANY | VERONA | PA |
| CRANE IRON WORKS | CATASAUQUA | PA |
| CRANE SUPPLY COMPANY | PITTSBURGH | PA |
| CRESCENT FORGINGS COMPANY | PITTSBURGH | PA |
| Crescent Iron | Philadelphia | PA |
| CRESCENT MINE | CALIFORNIA | PA |
| CRESCENT PORTLAND CEMENT COMPANY | CRESCENTDALE | PA |
| CRESCENT PORTLAND CEMENT COMPANY | WAMPUM | PA |
| CRESCENT WORKS | PITTSBURGH | PA |
| CRESMER FENCE COMPANY | EXTON | PA |
| CRESSONA ALUMINUM | CRESSONA | PA |
| CROFT AND ALLEN COMPANY | PHILADELPHIA | PA |
| CROMBY GENERATING STATION – POWER PLANT | PHOENIXVILLE | PA |
| CROMBY STATION PHILADELPHIA ELECTRIC | PHOENIXVILLE | PA |
| CROMPTON & KNOWLES | GIBRALTAR | PA |
| Cross Brothers | Philadelphia | PA |
| CROSS BROTHERS MEAT – 2ND STREET | PHILADELPHIA | PA |
| Cross Brothers Meat Packing | Philadelphia | PA |
| CROSS CREEK COAL COMPANY | DRIFTON | PA |
| CROSS CREEK COAL COMPANY | DERINGER | PA |
| CROSS CREEK COAL COMPANY | ONEIDA | PA |
| CROWN ASSOCIATED PRODUCTS | PHILADELPHIA | PA |
| CROWN CORK & SEAL – ASHTON ROAD | PHILADELPHIA | PA |
| Crown Cork and Seal | Philadelphia | PA |
| Crown Paperboard Company | Philadelphia | PA |
| CROWN PRODUCTS | PHILADELPHIA | PA |
| Crozier Medical Center | Chester | PA |
| CRUCIBLE COAL COMPANY | ANENSBURG | PA |
| Crucible Colt Industries | Midland | PA |
| Crucible Steel | Midland | PA |
| Crucible Steel | Pittsburgh | PA |
| Crucible Steel | Aliquippa | PA |
| Crucible Steel Co. | Primos | PA |
| CRUCIBLE STEEL CO. | MIDLAND | PA |
| Crucible Steel Company – Station 301 | Midland | PA |
| CRUCIBLE STEEL COMPANY OF AMERICA | PITTSBURGH | PA |
| CRUCIBLE STEEL COMPANY OF AMERICA | CLAIRTON | PA |
| CRUCIBLE STEEL COMPANY OF AMERICA | MIDLAND | PA |
| CRUCIBLE STEEL COMPANY OF AMERICA | BLAIR STATION | PA |
| CRUCIBLE STEEL COMPANY OF AMERICA – MIDLAND WORKS | MIDLAND | PA |
| CRUCIBLE STEEL COMPANY OF AMERICA, CRESCENTWORKS | PITTSBURGH | PA |
| CRUCIBLE STTEL | MIDLAND | PA |
| CRYSTAL ICE COMPANY, INCORPORATED | ALLEGHENY CITY | PA |
| CSX TRANSPORTATION | PHILADELPHIA | PA |
| CUDAHY PACKING COMPANY | PHILADELPHIA | PA |
| Culp Industrial Insulation | Kingston | PA |
| Culp Industrial Insulation | Kingstown | PA |
| Culp Industrial Insulation Co | Kingston | PA |
| CULP INDUSTRIAL INSULATION CO. | LOCK HAVEN | PA |
| CULP INDUSTRIAL INSULATION CO. | KINGSTON | PA |
| CUMBERLAND VALLEY DIVISION OF PENNSYLVANIA RAILROAD COMPANY | CHAMBERSBURG | PA |
| CUMBERLAND VALLEY RAILROAD COMPANY | CHAMBERSBURG | PA |
| CURTIN ELEM. SCHOOL | ALTOONA | PA |
| CURTIS PUBLISHING | PHILADELPHIA | PA |
| CURTIS PUBLISHING CO | SHARON HILL | PA |
| CURTIS PUBLISHING COMPANY | PHILADELPHIA | PA |
| Curtis-Wright Corporation Propeller Division | Beaver | PA |
| CUSTOM INSULATION COMPANY | YORK | PA |
| CYCLOPS CORPORATION | TITUSVILLE | PA |
| CYCLOPS CORPORATION | THUSVILLE | PA |
| CYTEMP SPECIALTY STEEL | TITUSVILLE | PA |
| D M TRAHAN PROJ SUPT – HOMER CITY STN SPUR | HOMER CITY | PA |
| D R BENDIX CO | PITTSBURGH | PA |
| D. LUTZ & SON BREWING COMPANY | ALLEGHENY | PA |
| D. LUTZ & SON BREWING COMPANY | ALLEGHENY CITY | PA |
| D. M. BARE PAPER COMPANY | ROARING SPRING | PA |
| D. OHER ENGINEERING COMPANY | PHILADELPHIA | PA |
| D. TRAINER AND SONS | LINWOOD | PA |
| D.B. FULLER | PHILADELPHIA | PA |
| D.L. CLARK COMPANY | ALLEGHENY | PA |
| D.L. MOLDEN AND BROTHER | PHILADELPHIA | PA |
| D.M. BARE AND COMPANY | ROARING SPRINGS | PA |
| D.M. BARE COMPANY | ROARING SPRINGS | PA |
| D.M. BARE PAPER COMPANY | ROARING SPRINGS | PA |
| D.O.E. | BRUCETON | PA |
| D.R. LANE | PITTSBURGH | PA |
| D.S. KEITH JUNIOR HIGH SCHOOL | ALTOONA | PA |
| DAGER AND COX, EUREKA PAPER MILLS | BRIDGEPORT | PA |
| Dail Rock Coal Company | Wyoming | PA |
| DALLY ENGINEERING VALVE C | PITTSBURGH | PA |
| DAMASCUS NICKEL STEEL COMPANY | CARNEGIE | PA |
| D’AMBROSIO CLOTHING | PHILADELPHIA | PA |
| DANA CORP. | READING | PA |
| DANA CORPORATION, PARISH FRAME DIVISION | READING | PA |
| DANIEL J. KEATING | PHILADELPHIA | PA |
| DANLEVY PACKING COMPANY | EAST LIBERTY | PA |
| DANVILLE AND SUNBURY STREET RAILWAY COMPANY | DANVILLE | PA |
| DANVILLE POWERHOUSE | WASHINGTONVILLE | PA |
| Danville State Hospital | Danville | PA |
| DANVILLE STOVE AND MANUFACTURING COMPANY | DANVILLE | PA |
| DANVILLE STRUCTURAL TUBING COMPANY | DANVILLE | PA |
| Darby Paper Company | Darby | PA |
| DARING PAPER COMPANY | BRIDGEPORT | PA |
| DARING PAPER COMPANY | DOWNINGTOWN | PA |
| DARLINGTON BUILDING | PHILADELPHIA | PA |
| DAUGHERTY REFINERY | PETROLIA | PA |
| DAUGHERTY REFINERY DIVISION | PETROLIA | PA |
| DAUGHERTY REFINERY DIVISION – DEPT A | PETROLIA | PA |
| Dauphin County Prison | Harrisburg | PA |
| DAVISON COKE AND IRON COMPANY | NEVILLE ISLAND | PA |
| Day & Zimmerman | Coatesville | PA |
| DAYS INN | BRISTOL | PA |
| DE WITT P HENRY CO | PHILADELPHIA | PA |
| Decker Associates Inc. | Orefield | PA |
| DECKER SQ STACK JOB | BALA CYNWYD | PA |
| DECORATING & DISPLAY STUDIO | LANCASTER | PA |
| DEFENSE PLANT CORPORATION | PHILADELPHIA | PA |
| DEFENSE PLANT CORPORATION, MARINE TURBINE PLANT | SOUTH PHILADELPHIA | PA |
| DEFENSE SUPPLY AGENCY | PHILADELPHIA | PA |
| Degol Brothers | Gallitzin | PA |
| DELANCY SCHOOL | PHILADELPHIA | PA |
| Delaware Alloy Forge | Philadelphia | PA |
| DELAWARE ALLOY FORGE CO | PHILADELPHIA | PA |
| DELAWARE AND HUDSON CANAL COMPANY | WILKES BARRE | PA |
| DELAWARE AND HUDSON COMPANY | PLYMOUTH JUNCTION | PA |
| DELAWARE AND HUDSON COMPANY | PROVIDENCE | PA |
| DELAWARE AND HUDSON COMPANY | SCRANTON | PA |
| DELAWARE AND HUDSON COMPANY | OLYPHANT | PA |
| DELAWARE AND HUDSON COMPANY | ARCHIBALD | PA |
| DELAWARE AND HUDSON COMPANY | CARBONDALE | PA |
| DELAWARE AND HUDSON COMPANY | PARSONS | PA |
| DELAWARE AND HUDSON COMPANY | WILKES BARRE | PA |
| DELAWARE AND HUDSON COMPANY | HUDSON | PA |
| DELAWARE AND HUDSON COMPANY – COAL MINING PLANT | CARBONDALE | PA |
| DELAWARE AND MAGNETIC SPRINGS RAILWAY COMPANY | PITTSBURGH | PA |
| Delaware Asbestos | Philadelphia | PA |
| DELAWARE COMPANY MEMORIAL HOSPITAL | DREXEL HILL | PA |
| DELAWARE COUNTY CENTRAL HEATING COMPANY | SPRINGFIELD | PA |
| Delaware County Courthouse | Media | PA |
| DELAWARE COUNTY ELECTRIC COMPANY – CHESTER STATION POWER PLANT | CHESTER | PA |
| DELAWARE COUNTY HOSPITAL | DELAWARE COUNTY | PA |
| DELAWARE COUNTY INCINERAT | CHESTER | PA |
| Delaware County Prison | Delaware County | PA |
| DELAWARE COUNTY PRISON | THORNTON | PA |
| DELAWARE INDUSTRIAL CHEM. CORP. | CHESTER | PA |
| Delaware Insulation Co | Lester | PA |
| DELAWARE LACKAWANNA AND WESTERN RAILROAD COMPANY | PLYMOUTH | PA |
| DELAWARE LACKAWANNA AND WESTERN RAILROAD COMPANY | SCRANTON | PA |
| DELAWARE LACKAWANNA AND WESTERN RAILROAD COMPANY, DIAMOND MINES | SCRANTON | PA |
| DELAWARE MINE | HUDSON | PA |
| DELAWARE RIVER CORDAGE MILL | PHILADELPHIA | PA |
| DELAWARE RIVER STEEL COMPANY | CHESTER | PA |
| Delaware Rubber & Asbestos | Philadelphia | PA |
| DELAWARE SHIP SUPPLY CO | PHILADELPHIA | PA |
| DELAWARE SHIP SUPPLY COMPANY | PHILADELPHIA | PA |
| DELAWARE STORAGE AND FREEZING COMPANY | PHILADELPHIA | PA |
| Delaware Valley Drywall | Croydon | PA |
| DELAWARE VALLEY HOSPITAL | LANGHORNE | PA |
| DELAWARE VALLEY PLASTICS CO. | PHILADELPHIA | PA |
| DELAWARE WATERSIDE STATION | PHILADELPHIA | PA |
| DELAWARE, LACKAWANNA & WESTERN RAILROAD COMPANY | PLYMOUTH | PA |
| DELAWARE, LACKAWANNA & WESTERN RAILROAD COMPANY | SCRANTON | PA |
| DELAWARE, LACKAWANNA & WESTERN RAILROAD COMPANY | NANTICOKE | PA |
| DELAWARE, LACKAWANNA & WESTERN RAILROAD COMPANY | KINGSTON | PA |
| DELAWARE, LACKAWANNA AND WESTERN RAILROAD COMPANY | TAYLOR | PA |
| DELAWARE, LACKAWANNA AND WESTERN RAILROAD COMPANY | SCRANTON | PA |
| DELAWARE, LACKAWANNA AND WESTERN RAILROAD COMPANY | NANTICOKE | PA |
| DELAWARE, LACKAWANNA AND WESTERN RAILROAD COMPANY | PLYMOUTH | PA |
| Delaware, Lackawanna, and Western RR | Scranton | PA |
| Delmont Builder Supply | Delmont | PA |
| Delta Equipment Co. (North American Smelting Co.) | Philadelphia | PA |
| DELTA FINISHING CO | PHILADELPHIA | PA |
| DELWORTH PAPER COMPANY | NEW CASTLE | PA |
| DENT PLUMBING & HEATING, INC. | LIGHT STREET | PA |
| DEPACO PAPER COMPANY | DOWNINGTON | PA |
| Department Of Motor Vehicles Building | Harrisburg | PA |
| DEPARTMENT OF PUBLIC WELFARE – PENNHURST STATE SCHOOL | SPRING CITY | PA |
| DEPARTMENT OF SAFETY | PHILADELPHIA | PA |
| DEPARTMENT OF THE INTERIOR, BUREAU OF MINES | PITTSBURGH | PA |
| DES MOINES STEEL | PITTSBURGH | PA |
| DESIGN TECHNIQUES | STROUDSBURG | PA |
| DETROIT STEEL PRODUCTS | WEST ELIZABETH | PA |
| Detroit Steel Products Company | Erie | PA |
| DEVAL CORPORATION | PHILADELPHIA | PA |
| DEWART MILK PRODUCTS COMPANY | TROUT RUN | PA |
| DEWITT P. HENRY CANDY COMPANY | PHILADELPHIA | PA |
| DEXTER PORTLAND CEMENT COMPANY | NAZARETH | PA |
| DEXTER PORTLAND CEMENT COMPANY | SIEGFRIED | PA |
| DIAMOND ALKALI COMPANY | PITTSBURGH | PA |
| DIAMOND DRILL MACHINE COMPANY | BIRDSBORO | PA |
| DIAMOND MINES | SCRANTON | PA |
| DIAMOND NATIONAL BANK BUILDING | PITTSBURGH | PA |
| DICKINSON SCHOOL OF LAW | CARLYLE | PA |
| DIETZ TRUCKING COMPANY, 166 39TH ST. | PITTSBURGH | PA |
| DILL AND COLLINS COMPANY | PHILADELPHIA | PA |
| DILLINGERS DISTILLERIES, INCORPORATED | RUFFSDALE | PA |
| DILWORTH PORTER AND COMPANY, LIMITED | PITTSBURGH | PA |
| DIRECTORS OF THE POOR OF ALLEGHENY COUNTY | WOODVILLE | PA |
| DISCON STEEL COMPANY – STEEL PLANT | FREELAND | PA |
| DISPATCH PUBLISHING COMPANY | PITTSBURGH | PA |
| DIVERSIFIED PRINTING | PARKESBURG | PA |
| DIVERSITECH GENERAL | JEANNETTE | PA |
| DIXIE CUP | EASTON | PA |
| DIXIE CUP PLANT | EASTON | PA |
| DIXMONT HOSPITAL FOR THE INSANE | DIXMONT | PA |
| DIXON VALVE AND COUPLING CO | PHILADELPHIA | PA |
| DODGE MINES | SCRANTON | PA |
| DODGE STEEL CO | PHILADELPHIA | PA |
| DODGE STEEL COMPANY | PHILADELPHIA | PA |
| DODSON MINES, PLYMOUTH COAL COMPANY | PLYMOUTH | PA |
| DOEHLER-JARVIS DIVISION, NATIONAL LEAD INDUSTRIES, INCORPORATED | POTTSTOWN | PA |
| D’OLIER ENGINEERING COMPANY | PHILADELPHIA | PA |
| DOLONITE BRICK CORP. OF AMERICA | YORK | PA |
| DOLPH COAL COMPANY | DUNMORE | PA |
| DOLPH COAL COMPANY | SCRANTON | PA |
| DOLPH COAL COMPANY | WINTON | PA |
| DOLPH COAL COMPANY | PICKVILLE | PA |
| DOMINO SUGAR | PHILADELPHIA | PA |
| Domino Sugar Refinery | Philadelphia | PA |
| DON SOTERO ESCARZA | INGO PORTUGALETE | PA |
| DONALDSON IRON COMPANY | EMANS | PA |
| DONALDSON IRON COMPANY | EMAUS | PA |
| Donegon School | Bethlehem | PA |
| DONORA BREWING COMPANY | DONORA | PA |
| DONORA ZINC WORKS | DONORA | PA |
| DONOVAN CEMENT | PHILADELPHIA | PA |
| DONOVAN COMPANY | PHILADELPHIA | PA |
| DORCHESTER APARTMENTS | PLYMOUTH MEETING | PA |
| DORR OLIVER INC | HAZELTON | PA |
| DORR OLIVER, INCORPORATED | HAZELTOEN | PA |
| DORR OLIVER, INCORPORATED | SPRING GROVE | PA |
| Double Woven Corp. | Scranton | PA |
| Double Woven Corporation of America | Dunmore | PA |
| DOUGHERTY BACHRAN | PHILADELPHIA | PA |
| DOWNINGTOWN WATER POLLUTI | DOWNINGTOWN | PA |
| Dowty Corporation | Zelienople | PA |
| DOYLE AND COMPANY | PHILADELPHIA | PA |
| DOYLESTOWN AND EASTON STREET RAILWAY COMPANY | DOYLESTOWN | PA |
| DOYLESTOWN AND WILLOW GROVE RAILWAY COMPANY | PHILADELPHIA | PA |
| DOYLESTOWN HOSPITAL – WEST STATE STREET | DOYLESTOWN | PA |
| Dr. Lawrence Siegel’s residence | Yardley | PA |
| DR. W.A. DRYSDALE | PHILADELPHIA | PA |
| DRAKE HOTEL | PHILADELPHIA | PA |
| Draper & Yost, Incorporated | Tamaqua | PA |
| DRAVO CONTRACTING COMPANY | PITTSBURGH | PA |
| DRAVO CORP | NEVILLE ISLAND | PA |
| DRAVO CORP | PITTSBURGH | PA |
| Dravo Corp. | Neville Island | PA |
| Dravo Corporation | Neville Island | PA |
| DRAVO CORPORATION | PHILADELPHIA | PA |
| DRAVO CORPORATION | PITTSBURGH | PA |
| DRAVO CORPORATION | NEW BRIGHTON | PA |
| DRAVO DOYLE COMPANY | PITTSBURGH | PA |
| Dravo Shipbuilding | Neville Island | PA |
| Dravo Shipbuilding | Pittsburgh | PA |
| DREDGE PHILADELPHIA | CHESTER | PA |
| Dresser Manufacturing | Wellsboro | PA |
| Dresser Manufacturing Division | Bradford | PA |
| DREVER | BETHAYRES | PA |
| DREVER CO | BETHAGRES | PA |
| DREVER COMPANY | BETHAYRES | PA |
| DREVER COMPANY, BUILDING # 1 | BETHAYRES | PA |
| DREVER COMPANY, BUILDING # 2 | BETHAYRES | PA |
| Drexel Institute | Philadelphia | PA |
| DRIGGS SEABURY ORDNANCE COMPANY | SHARON | PA |
| DUBOIS ELECTRIC AND TRACTION COMPANY – POWER PLANT | DUBOIS | PA |
| Dubois Hospital | Dubois | PA |
| DUBOIS HOSPITAL – HOSPITAL AVENUE | DUBOIS | PA |
| DUER SPRING AND MFG CO DIV | MCKEES ROCKS | PA |
| DUFF MANUFACTURING COMPANY | PITTSBURGH | PA |
| DUFF-NORTON MANUFACTURING COMPANY | PITTSBURGH | PA |
| DUGGAN & MARCON, INCORPORATED | ALLENTOWN | PA |
| DUNBAR FURANCE COMPANY | DUNBAR | PA |
| DUNHAM-BUSH | HARRISBURG | PA |
| DUNLEVY AND BROTHER COMPANY | EAST LIBERTY | PA |
| DUNMORE IRON AND STEEL COMPANY | DUNMORE | PA |
| DUPLAN SILK CORPORATION | HAZLETON | PA |
| Dupont | Philadelphia | PA |
| DUPONT CHEMICAL | KENNETT SQUARE | PA |
| DUPONT CHEMICAL | PHILADELPHIA | PA |
| DUQUESNE BREWING CO. – BOTTLING HOUSE | PITTSBURGH | PA |
| DUQUESNE BREWING CO. OF PITTSBURGH – NEW BOTTLING HOUSE | PITTSBURGH | PA |
| DUQUESNE BREWING COMPANY | PITTSBURGH | PA |
| DUQUESNE BREWING COMPANY | MCKEES ROCKS | PA |
| Duquesne Club | Pittsburgh | PA |
| DUQUESNE FORGE COMPANY | RANKIN | PA |
| DUQUESNE FORGE COMPANY | PITTSBURGH | PA |
| DUQUESNE ICE COMPANY | PITTSBURGH | PA |
| DUQUESNE INCINERATOR | DUQUESNE | PA |
| DUQUESNE LIGHT – CHESWICK POWER PLANT | CHESWICK | PA |
| DUQUESNE LIGHT – ELRAMA POWER PLANT | ELRAMA | PA |
| Duquesne Light Co | Cheswick | PA |
| Duquesne Light Co | Shipping Port | PA |
| DUQUESNE LIGHT CO | ELRAMA | PA |
| DUQUESNE LIGHT CO | PITTSBURGH | PA |
| DUQUESNE LIGHT CO – BEAVER VALLEY NUCLEAR POWER PLANT | Shippingport | PA |
| Duquesne Light Co – Cheswick Power Station | Springdale | PA |
| DUQUESNE LIGHT CO – CHESWICK STATION | SPRINGDALE | PA |
| Duquesne Light Co – Elrama Power Plant | ELRAMA | PA |
| Duquesne Light Co – Elrama Power Plant – Storeroom | ELRAMA | PA |
| Duquesne Light Co – Frank R. Phillips Power Station | WIRETON | PA |
| Duquesne Light Co – Shippingport Nuclear Power Station | SHIPPINGPORT | PA |
| DUQUESNE LIGHT CO -PHILLIPS POWER PLANT – STOREROOM | WIRETON | PA |
| Duquesne Light Co Phillips Power Station | South Heights | PA |
| Duquesne Light Co. – Brunot Island Generating Station | Pittsburgh | PA |
| Duquesne Light Co. – Brunot Island Generating Station – Storeroom | Pittsburgh | PA |
| DUQUESNE LIGHT CO. – ELRAMA POWER STATION | Jefferson Hills | PA |
| Duquesne Light Co.- Frank R. Phillips Power Station | Cheswick | PA |
| DUQUESNE LIGHT CO-CENTRAL STR | PITTSBURGH | PA |
| Duquesne Light Company | Pittsburgh | PA |
| Duquesne Light Company | Shippingport | PA |
| DUQUESNE LIGHT COMPANY | ELRAMA | PA |
| DUQUESNE LIGHT COMPANY – 13TH STREET PLANT | PITTSBURGH | PA |
| DUQUESNE LIGHT COMPANY – 20TH STREET STATION | PITTSBURGH | PA |
| DUQUESNE LIGHT COMPANY – 30TH STREET STATION | PITTSBURGH | PA |
| DUQUESNE LIGHT COMPANY – BRUNOT ISLAND GENERATING STATION | PITTSBURGH | PA |
| DUQUESNE LIGHT COMPANY – CHESWICK #1 | CHESWICK/SPRINGDALE | PA |
| DUQUESNE LIGHT COMPANY – Cheswick Station | CHESWICK | PA |
| DUQUESNE LIGHT COMPANY – CHESWICK STATION | SPRINGDALE | PA |
| DUQUESNE LIGHT COMPANY – COLFAX POWER STATION | SPRINGDALE | PA |
| DUQUESNE LIGHT COMPANY – COMBINED CYCLE PLANT | PITTSBURGH | PA |
| DUQUESNE LIGHT COMPANY – ELRAMA POWER PLANT | ELRAMA | PA |
| DUQUESNE LIGHT COMPANY – ELRAMA POWER STATION – WASHINGTON COUNTY | ELRAMA | PA |
| DUQUESNE LIGHT COMPANY – GLENWOOD STATION | PITTSBURGH | PA |
| DUQUESNE LIGHT COMPANY – GRANT STATION | PITTSBURGH | PA |
| Duquesne Light Company – James H. Reed Power Station | Pittsburgh | PA |
| DUQUESNE LIGHT COMPANY – PHIPPS POWER PLANT | PITTSBURGH | PA |
| DUQUESNE LIGHT COMPANY – POWER STATION | RANKIN | PA |
| DUQUESNE LIGHT COMPANY – SHIPPINGPORT #1 | SHIPPINGPORT | PA |
| DUQUESNE LIGHT COMPANY – SHIPPINGPORT ATOMIC POWER STATION | SHIPPINGPORT | PA |
| DUQUESNE LIGHT COMPANY- BEAVER VALLEY NUCLEAR POWER PLANT | SHIPPINGPORT | PA |
| DUQUESNE LIGHT COMPANY- CHESWICK STATION | SPRINGDALE | PA |
| DUQUESNE LIGHT COMPANY- ELRAMA POWER PLANT | ELRAMA | PA |
| DUQUESNE STEEL COMPANY | COCHRAN STATION | PA |
| DUQUESNE STEEL WORKS | COCHRAN STATION | PA |
| DUQUESNE STEEL WORKS | DUQUESNE | PA |
| Duquesne Works | Duquesne | PA |
| DURALOY COMPANY | SCOTTDALE | PA |
| DURHAM PUBLIC SCHOOL | PHILADELPHIA | PA |
| DUTTON PLACE APTS | FOLSOM | PA |
| DYNAMET INC | WASHINGTON | PA |
| DYNAMIC METAL FORMING, INCORPORATED | KOPPEL | PA |
| Dynamit Nobel of America, Inc. | Mountain Top | PA |
| Dyna-Vac Power Cleaning of Buxmont | Doylestown | PA |
| E I Dupont De Nemours & Co | Twin Oaks | PA |
| E BERGENDAHL CO | PHILADEPHIA | PA |
| E I DUPONT DE NEMOURS | CORNWELLS HEIGHTS | PA |
| E I DUPONT DENEMOURS | WASHINGTON | PA |
| E Keeler | Williamsport | PA |
| E KEELER CO | WILLIAMSPORT | PA |
| E S Atkinson | Erie | PA |
| E Thompson Works | Braddock | PA |
| E. & G. BROOKE IRON COMPANY | BIRDSBORO | PA |
| E. & G. BROOKE IRON COMPANY | ST. PETERS | PA |
| E. & G. BROOKE PLANT | BIRDSBORO | PA |
| E. BERGENDAHL | PHILADELPHIA | PA |
| E. J. LAVINO & COMPANY | SHERIDAN | PA |
| E. KEELER CO. | WILLIAMSPORT | PA |
| E. Keeler Company | Williamsport | PA |
| E. STROUDSBURG STATE TEACHERS COLLEGE – BOILER HOUSE ADDITION | EAST STROUDSBURG | PA |
| E. T. Stotesbury Residence | Philadelphia | PA |
| E.B. LEAF COMPANY | PHILADELPHIA | PA |
| E.C. KNIGHT AND COMPANY | PHILADELPHIA | PA |
| E.F. HOUGHTON AND COMPANY | PHILADELPHIA | PA |
| E.G. Budd Company | Philadelphia | PA |
| E.I. DU PONT DE NEMOURS & COMPANY | PHILADELPHIA | PA |
| E.I. DU PONT DE NEMOURS & COMPANY | GIBBSTOWN | PA |
| E.I. DU PONT DE NEMOURS & COMPANY | CORNWELLIS HEIGHTS | PA |
| E.I. Du Pont De Nemours | Philadelphia | PA |
| E.I. Dupont de Nemours & Company | Philadelphia | PA |
| E.I. DUPONT DE NEMOURS & COMPANY | HAZELTON | PA |
| E.J. LAVINO & COMPANY | PHILADELPHIA | PA |
| E.J. LAVINO & COMPANY | PLYMOUTH MEETING | PA |
| E.J. LAVINO & COMPANY | SHERIDAN | PA |
| E.J. LAVINO AND COMPANY | SHERIDAN | PA |
| E.J. LAVINO AND COMPANY | MARIETTA | PA |
| E.L. ROTHSCHILD BUILDING | PHILADELPHIA | PA |
| E.l. Weigland | Pittsburgh | PA |
| E.M. AND W. FERGUSON | PITTSBURGH | PA |
| E.N. Hyde Heating Company | Pittsburgh | PA |
| E.S. & ATKINSON | ERIE | PA |
| E.S. FOX & CO. | READING | PA |
| E.S. FOX DIV., NORTHEASTERN LUMBER CO. | READING | PA |
| E.T. EDWARDS | COLUMBIA | PA |
| E.W. BLISS | MIDLAND | PA |
| E.W. BLISS | PITTSBURGH | PA |
| E.W. BLISS COMPANY | MIDLAND | PA |
| E.W. RHODES MIDDLE SCHOOL – WEST CLEARFIELD STREET | PHILADELPHIA | PA |
| EAGLE HILL COLLIERY | PORT CARBON | PA |
| EARBEU HARDING AND COMPANY | PHILADELPHIA | PA |
| EAST BOSTON COLLIERY | KINGSTON | PA |
| EAST BROAD TOP RAILROAD AND COAL COMPANY | ORBISONIA | PA |
| EAST BROAD TOP RAILROAD COMPANY | ORBISONIA | PA |
| EAST END ELECTRIC LIGHT COMPANY – POWER PLANT | EAST LIBERTY | PA |
| EAST END ELECTRIC LIGHT COMPANY – POWER PLANT | PITTSBURGH | PA |
| EAST HEMPFIELD ELEM. SCHOOL | GREENSBURG | PA |
| EAST LEHIGH COLLIERY | TAMAQUA | PA |
| EAST LIBERTY | PITTSBURGH | PA |
| EAST LIBERTY HOME DRESSED MEAT COMPANY | PITTSBURGH | PA |
| EAST LIBERTY MARKET | PITTSBURGH | PA |
| EAST PENN REFRACTORIES | READING | PA |
| EAST PENN REFRACTORIES CO | READING | PA |
| EAST PENNSYLVANIA ELECTRIC COMPANY – POWER PLANT | PINE GROVE | PA |
| EAST PETERSBURG ELEMENTARY SCHOOL – LEMON STREET | EAST PETERSBURG | PA |
| EAST PITTSBURGH WATER COMPANY – EAST PITTSBURGH WATER WORKS | EAST PITTSBURGH | PA |
| EAST SENIOR HIGH SCHOOL | WEST CHESTER | PA |
| EAST STROUDSBURG STATE TEACHERS COLLEGE – INFIRMARY BUILDING | EAST STROUDSBURG | PA |
| EASTERN AFFILIATED SERVICES CORP | EASTON | PA |
| EASTERN ASPHALT COMPANY | PHILADELPHIA | PA |
| EASTERN FOUNDRY CO | BOYENTOWN | PA |
| EASTERN FOUNDRY CO | BOYERTOWN | PA |
| EASTERN FOUNDRY COMPANY | BOYERTOWN | PA |
| EASTERN FOUNDRY COMPANY | HOVERTOWN | PA |
| EASTERN GUNITE CORPORATION | BALA CYNWYD | PA |
| EASTERN HYDRAULIC PRESS BRICK COMPANY | PHILADELPHIA | PA |
| EASTERN INDUSTRIAL INSULATION | ALLENTOWN | PA |
| EASTERN INDUSTRIAL INSULATION | READING | PA |
| Eastern Industrial Insulation Co | Reading | PA |
| EASTERN MERCY HEALTH SYSTEMS | PITTSBURGH | PA |
| EASTERN PENN PSYCHIATRIC INSTITUTE | PHILADELPHIA | PA |
| EASTERN PENNSYLVANIA POWER COMPANY – EASTON POWER PLANT | EASTON | PA |
| EASTERN PENNSYLVANIA RAILWAYS COMPANY | POTTSVILLE | PA |
| EASTERN PENNSYLVANIA RAILWAYS COMPANY | PALO ALTO | PA |
| EASTERN STATE SCHOOL | LANGHORNE | PA |
| EASTERN STATE SCHOOL | NESHAMINY | PA |
| EASTERN STEEL COMPANY | POTTSVILLE | PA |
| EASTON GAS AND ELECTRIC COMPANY – POWER PLANT | EASTON | PA |
| EASTON HIGH SCHOOL | EASTON | PA |
| Easton Hospital | Easton | PA |
| EASTON SHOPPING CENTER | EASTON | PA |
| Eaton Corporation | Philadelphia | PA |
| EATON CORPORATION | BEAVER | PA |
| EBENSBURG COAL COMPANY | COLVER | PA |
| EBENSBURG LIGHT, HEAT AND POWER COMPANY – POWER PLANT | EBENSBURG | PA |
| EBERHARD FABER COMPANY – PENCIL PLANT | MOUNTAIN TOP | PA |
| EBERLE TANNING COMPANY | WESTFIELD | PA |
| ECONOLODGE | LEVITTOWN | PA |
| Economy Sauer Chatham Center | Pittsburgh | PA |
| EDDYSTONE GENERATING STATION | EDDYSTONE | PA |
| Eddystone Manufacturing Company | Eddystone | PA |
| EDDYSTONE MFG CO | EDDYSTONE | PA |
| EDDYSTONE POWERHOUSE | EDDYSTONE | PA |
| Eddystone Station | Eddystone | PA |
| EDDYSTONE STATION | PHILADELPHIA | PA |
| Eddystone Steel | North Eddystone | PA |
| EDENSBURG COAL COMPANY | COLVER | PA |
| EDENSBURG POWER | EBENSBURG | PA |
| EDGAR THOMPSON STEEL WORKS | BESSEMER | PA |
| EDGAR THOMPSON WORKS | BRADDOCK | PA |
| EDGECOMB STEEL | PHILADELPHIA | PA |
| Edgewater Corp | Oakmont | PA |
| EDGEWATER CORP. | PITTSBURGH | PA |
| Edgewater Corporation | Oakmont | PA |
| EDGEWATER CORPORATION | PITTSBURGH | PA |
| EDGEWATER STEEL | OAKMONT | PA |
| EDGEWATER STEEL CO | VERONA | PA |
| EDGEWATER STEEL COMPANY | OAKMONT | PA |
| EDGEWATER STEEL COMPANY | PITTSBURGH | PA |
| EDGEWATER STEEL COMPANY | OAKMONT ALLEGHENY COUNTY | PA |
| EDGEWATER STEEL COMPANY | VERONA | PA |
| Edgewater Steel Corporation | Oakmont | PA |
| EDGEWOOD MILL | SHAMOKIN | PA |
| EDINBORO STATE COLLEGE – STADIUM | EDINBORO | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – ALTOONA PLANT | ALTOONA | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – ELECTRIC LIGHT PLANT | HAZLETON | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – ELECTRICAL PLANT | MT. CARMEL | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – POWER PLANT | SUNBURY | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – POWER PLANT | LANCASTER | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – POWER PLANT | WEST CHESTER | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – POWER PLANT | SHAMOKIN | PA |
| EDISON ELECTRIC ILLUMINATING COMPANY – POWER PLANT | BELLEFONTE | PA |
| EDISON ELECTRIC LIGHT COMPANY – GENERATING PLANT | PHILADELPHIA | PA |
| EDISON ELECTRIC LIGHT COMPANY – POWER PLANT | YORK | PA |
| EDISON INTERNATIONAL | HOMER CITY | PA |
| EDISON MISSION ENERGY | HOMER CITY | PA |
| EDITH FURNACE | ALLEGHENY | PA |
| EDWARD FAY AND SON | PHILADELPHIA | PA |
| EDWIN HARRINGTON SON AND COMPANY | PHILADELPHIA | PA |
| EHRET MAGNESIA MANUFACTURING COMPANY | PORT KENNEDY | PA |
| Ehret-Magnesium Mfg. (Fuller-Austin) | Valley Forge | PA |
| Einstein Medical Center | Philadelphia | PA |
| EINSTEIN MEDICAL CENTER, SOUTHERN DIVISION | PHILADELPHIA | PA |
| EISENHOWER APARTMENTS | READING | PA |
| Electra Products Company | Lansdale | PA |
| Electralloy Corp | Oil City | PA |
| ELECTRIC AUTOLITE COMPANY | HAZELTON | PA |
| ELECTRIC COMPANY OF AMERICA – LAND TITLE BUILDING | PHILADELPHIA | PA |
| Electric Storage Battery Co. | Philadelphia | PA |
| ELECTRIC STORAGE BATTERY COMPANY | PHILADELPHIA | PA |
| Electric Storage Battery Company – Manufacturing Plant | Philadelphia | PA |
| ELECTRO ALLOY | OIL CITY | PA |
| Electro Chemicals | Emmaus | PA |
| ELECTROTHERM CORP | PHILADELPHIA | PA |
| ELEMENTIS PIGMENTS, INCORPORATED | EASTON | PA |
| ELENGER IND. | MOSCOW | PA |
| ELEVENTH WARD SCHOOL | ALLEGHENY | PA |
| ELIZA PIPE SHOP | MCKEES ROCKS | PA |
| ELIZABETH STEEL MAGEE HOSPITAL | PITTSBURGH | PA |
| ELIZABETH STEET MAGEE HOSPITAL | PITTSBURGH | PA |
| ELJER CO | FORD CITY | PA |
| ELK TANNING COMPANY | COUDERSPORT | PA |
| ELK TANNING COMPANY | CURWENSVILLE | PA |
| ELKLAND LEATHER COMPANY | ELKLAND | PA |
| ELLECTRALLOY CORPORATION | OIL CITY | PA |
| ELLIOT CO | JEANETTE | PA |
| ELLIOT COMPANY | JEANNETTE | PA |
| ELLIOT COMPANY | RIDGWAY | PA |
| ELLIOT COMPANY DIVISION OF CARRIER | JEANETTE | PA |
| ELLIOT STEEL COMPANY | JEANETTE | PA |
| ELLIOTT CO | JEANNETTE | PA |
| ELLIOTT COMPANY | JEANNETTE | PA |
| ELLIOTT COMPANY | RIDGWAY | PA |
| Elliott Company – Accoustical Lab | Ridgeway | PA |
| ELLIOTT COMPANY – DIVISION OF CARRIER | JEANETTE | PA |
| ELLIOTT COMPANY PLANT | JEANNETTE | PA |
| ELLIOTT TURBOMACHINERY COMPANY, INCORPORATED | JEANNETTE | PA |
| ELLIS SCHOOL | PITTSBURGH | PA |
| ELLSWORTH COAL COMPANY | ELLSWORTH | PA |
| ELLSWORTH COAL COMPANY | COKEBURG | PA |
| ELLSWORTH COLLIERIES COMPANY | ELLSWORTH, WASHINGTON COUNTY | PA |
| Ellwood City Forge | Ellwood City | PA |
| ELLWOOD CITY FORGE CORP | ELLWOOD CITY | PA |
| ELLWOOD CITY MUNICIPAL ELECTRIC DEPARTMENT – ELECTRIC PLANT | ELLWOOD CITY | PA |
| ELRAMA POWER PLANT | ELRAMA | PA |
| ELRAMA POWER STATION | Elrama | PA |
| ELRAMA POWER STATION – WASHINGTON COUNTY | ELRAMA | PA |
| Elrama Powerhouse | Elrama | PA |
| ELWOOD CITY FORGE | ELLWOOD CITY | PA |
| ELWYN TRAINING SCHOOL | ELWYN | PA |
| EMBREEVILLE STATE HOSPITA | EMBREEVILLE | PA |
| EMLENTON REFINING COMPANY | EMLENTON | PA |
| EMMAUS THEATRE | EMMAUS | PA |
| EMPIRE BUILDING | PITTSBURGH | PA |
| EMPIRE IRON AND STEEL COMPANY | CATASAUQUA | PA |
| EMPIRE IRON AND STEEL COMPANY | MACUNGIE | PA |
| EMPIRE MILLS | PHILADELPHIA | PA |
| EMPIRE REEVES STEEL CORPORATION | PITTSBURGH | PA |
| EMPIRE STEEL PRODUCTS | TEMPLE | PA |
| ENAMEL PRODUCTS & PLATING COMPANY | McKEESPORT | PA |
| ENAMELSTRIP CORPORATION | ALLENTOWN | PA |
| ENG RESEARCH BLD 19 TEST COIL | YORK | PA |
| ENGR ANNEX | PITTSBURGH | PA |
| ENTERPRISE GALVANIZING | PHILADELPHIA | PA |
| EPISCOPAL ACADEMY – SWIMMING POOL | MERION | PA |
| EPISCOPAL HOSPITAL | PHILADELPHIA | PA |
| EPSILON ZETA ALUMNI ASSOCIATION | PHILADELPHIA | PA |
| EQUIPMENT ENGINEERING COMPANY | PITTSBURGH | PA |
| EQUIPMENT ENIGNEERING CO | PITTSBURGH | PA |
| EQUITABLE GAS – HEATING AND COOLING PLANT | PITTSBURGH | PA |
| EQUITABLE GAS COMPANY – GAS PLANT | ELRAMA | PA |
| Equitable Gas Energy Co. | Pittsburgh | PA |
| Equitable Gas Energy Co. | Waynesburg | PA |
| EQUITABLE LIFE ASSURANCE SOCIETY – GATEWAY CENTER – BASEMENT STOCKROOM 1 | PITTSBURGH | PA |
| ERBEN HARDING COMPANY | TACONY | PA |
| ERBEN HARDING COMPANY | PHILADELPHIA | PA |
| ERIC C HOLZER | CHESTER | PA |
| ERIE CAMBRIDGE UNION AND CORRY RAILWAY COMPANY | MILL VILLAGE | PA |
| ERIE CAR WORKS, LIMITED | ERIA | PA |
| Erie City Energy Division | Erie | PA |
| Erie City Iron Works | Erie | PA |
| ERIE COKE COMPANY | ERIE | PA |
| Erie County Courthouse | Erie | PA |
| ERIE COUNTY ELECTRIC COMPANY – POWER STATION | ERIE | PA |
| ERIE ELECTRIC MOTOR COMPANY – POWER STATION | ERIE | PA |
| Erie Forge & Steel | Erie | PA |
| ERIE FORGE & STEEL CORP. | ERIE | PA |
| ERIE FORGE AND STEEL COMPANY | ERIE | PA |
| Erie Industrial Insulation | Mckean | PA |
| ERIE LACKAWANNA RAILROAD – PENNSYLVANIA STATE POLICE – TEAM TRACK – OBLATES OF ST. JOSEPH | KINGSTON | PA |
| ERIE LACKAWANNA RAILROAD – PUBLIC SIDING | KINGSTON | PA |
| ERIE LACKAWANNA RAILROAD – TEAM TRACK | KINGSTON | PA |
| Erie Lighting Co. | Erie | PA |
| ERIE LIGHTING COMPANY – POWER STATION | ERIE | PA |
| ERIE MALLEABLE IRON COMPANY | Erie | PA |
| ERIE MARINE | ERIE | PA |
| Erie Railroad Co. | Meadville | PA |
| ERIE RAILROAD COMPANY | DUNMORE | PA |
| ERIE RAILROAD COMPANY | SUSQUEHANNA | PA |
| ERIE RAILROAD COMPANY | MEADVILLE | PA |
| ERIE WORKS | ERIE | PA |
| Erwin Plumbing | Philadelphia | PA |
| ES MAGEE HOSPITAL | PITTSBURGH | PA |
| ESAB | Hanover | PA |
| ESAB | York | PA |
| ESSO STANDARD OIL COMPANY | PITTSBURGH | PA |
| ESTATE OF H.W. OLIVER | PITTSBURGH | PA |
| ESTATE OF HENRY W. OLIVER | PITTSBURGH | PA |
| ESTATE OF JAMES LORD JR. | PHILADELPHIA | PA |
| ESTATE OF STEPHEN GREENE | PHILADELPHIA | PA |
| ESTATE OF WILLIAM WEIGHTMAN | PHILADELPHIA | PA |
| ETERNO ASBESTOS LUMBER AND SHINGLE COMPANY | REDINGTON | PA |
| EUREKA | KINGSTON | PA |
| EUREKA #30 | SCALP LEVEL | PA |
| EUREKA #7 | BEULAH | PA |
| EUREKA COLLIERY #35 | WINDBER | PA |
| Eureka Div Of Litton Ind | Dunmore | PA |
| EUREKA LIMESTONE – TANK INSULATION | PHILADELPHIA | PA |
| EUREKA SPECIALTY CO. | SCRANTON | PA |
| EUREKA STONE QUARRY INCORPORATED – BUCKS COUNTY | EUREKA | PA |
| EUREKA STONE QUARRY, INCORPORATED | EUREKA | PA |
| EUREKA STONE QUARRY, INCORPORATED | CHALFONT | PA |
| EUREKA STONE QUARRY, INCORPORATED | CHALFOND | PA |
| EUREKA STONE QUARRY, INCORPORATED | BUCKS COUNTY | PA |
| EUREKA STONE QUARRY, INCORPORATED, TANK INSULATION | PHILADELPHIA | PA |
| EVANS COLLIERY COMPANY | HAZELTON | PA |
| Evans Memorial | Philadelphia | PA |
| EVERTS AND OVERDEER, INCORPORATED | LANCASTER | PA |
| Ew Bowman Inc | Uniontown | PA |
| EWEN BREAKER | PITTSTON | PA |
| Excelsior Brass | Reading | PA |
| EXCELSIOR COAL COMPANY | EXCELSIOR | PA |
| EXCELSIOR STEAM PLANNING MILL | MAUCH CHUNK | PA |
| EXCHANGE BUILDING | PHILADELPHIA | PA |
| EXELON POWER | PHOENIXVILLE | PA |
| EXELON POWER | EDDYSTONE | PA |
| EXETER COLLIERY | PITTSTON | PA |
| EXETER COLLIERY | WEST PITTSTON | PA |
| EXETER HIGH SCHOOL | EXETER | PA |
| EXETER MACHINE WORKS | PITTSTON | PA |
| EXETER POWER COMPANY – POWER PLANT | PITTSTON | PA |
| EXIDE BATTERY | PHILADELPHIA | PA |
| EXIDE BATTERY COMPANY | PHILADELPHIA | PA |
| EXOTIC METALS | RIDGWAY | PA |
| EXTON MALL | EXTON | PA |
| Extrusion Die Makers | Murrysville | PA |
| F B Wright Company | Bridgeville | PA |
| F B Wright Company | Pittsburgh | PA |
| F M C CORP | KENNETT SQUARE | PA |
| F. & M. SCHAEFER BREWING COMPANY | TREXLERTOWN | PA |
| F. MILLER SPRING & MANUFACTURING COMPANY | PITTSBURGH | PA |
| F.A. PAVLICK | FAIRLESS HILLS | PA |
| F.A. POTH AND SONS | PHILADELPHIA | PA |
| F.A. POTH BREWING COMPANY | PHILADELPHIA | PA |
| F.C. ROBERTS | PHILADELPHIA | PA |
| F.C. ROBERTS AND COMPANY | PHILADELPHIA | PA |
| F.C. ROBERTS AND COMPANY ENGINEERS | PHILADELPHIA | PA |
| F.C. ROBERTS COMPANY ENGINEERS | PHILADELPHIA | PA |
| F.F. GEISLER AND COMPANY | PITTSBURGH | PA |
| F.G. VOGT AND SONS | PHILADELPHIA | PA |
| F.H. KALBFLEISCH CORPORATION | ERIE | PA |
| F.R. DRAVO AND COMPANY | PITTSBURGH | PA |
| F.S. EDMONDS SCHOOL – THOURON AVENUE | PHILADELPHIA | PA |
| F.W DARLINGTON C.E. | PHILADELPHIA | PA |
| F.W. TUNNELL GLUE MANUFACTURING | PHILADELPHIA | PA |
| FABRICATING ENGINEERING C | YORK | PA |
| FABRICATING ENGINEERING, INCORPORATED | YORK | PA |
| FAIRHILL APARTMENTS | PHILADELPHIA | PA |
| Fairless Hills Steel Mill | Morrisville | PA |
| Fairless Steel | Fairless Hills | PA |
| FAIRLESS WORKS | FAIRLESS HILLS | PA |
| FAIRLESS WORKS – #2 CONTINUOUS ANNEALING LINE | MORRISVILLE | PA |
| Fairless Works US Steel | Fairless | PA |
| FAIRMOINT WOOSTER MILLS | PHILADELPHIA | PA |
| Fairmont Supply Co | Washington | PA |
| Fairmont Supply Company | Washington | PA |
| FAIRMOUNT PARK COMMISSION | PHILADELPHIA | PA |
| FAIRMOUNT PARK TRANSPORTATION COMPANY | PHILADELPHIA | PA |
| FAIRVIEW SCHOOL – SOUTH ERIE PENNA | FAIRVIEW | PA |
| FALCON EQUIPMENT CO | NEW BRIGHTON | PA |
| Fanny Farmers Candy Manufacturing | Harrisburg | PA |
| FARENTUM BOROUGH | TARENTUM | PA |
| Farm Show Building | Harrisburg | PA |
| FARMERS BANK BUILDING | PITTSBURGH | PA |
| FARMERS CHEESE | NEW WILMINGTON | PA |
| FARMERS DEPOSIT NATIONAL BANK BUILDING | PITTSBURGH | PA |
| FARRELL STEEL WORKS AND FURNACES | FARRELL | PA |
| FAUST DISTILLERY | GLEN ROCK | PA |
| FAWCUS MACHINE COMPANY | FORD CITY | PA |
| FAYETTE CTY | NEWELL | PA |
| FAYETTE MANUFACTURING COMPANY | CHESTER | PA |
| FAYETTE R. PLUMB, INCORPORATED | PHILADELPHIA | PA |
| FAZEKAS FRANK | EASTON | PA |
| FEDERAL CONTAINER COMPANY | PHILADELPHIA | PA |
| FEDERAL ENAMELING AND STAMPING COMPANY | MCKEES ROCKS | PA |
| FEDERAL LABORATORIES INC | SALTSBURG | PA |
| FEDERAL OFFICE BLDG | PITTSBURGH | PA |
| FEDERAL OFFICE BUILDING | PHILADELPHIA | PA |
| FEDERAL OFFICE BUILDING – WALNUT STREET | HARRISBURG | PA |
| FEDERAL OFFICE BUILDING & COURTHOUSE – 6TH & ARCH STREETS | PHILADELPHIA | PA |
| FEDERAL PAPER BOARD COMPANY, INCORPORATED, PAPER BOARD DIVISION | READING | PA |
| FEDERAL RESERVE BANK OF PHILADELPHIA | PHILADELPHIA | PA |
| FEDERAL SAVINGS BANK | ARDMORE | PA |
| FEDERAL SHIPBUILDING AND DRY DOCK CO. OF U.S. | PITTSBURGH | PA |
| FEDERAL STEEL FOUNDRY COMPANY | CHESTER | PA |
| Federal Street Freight Station | Philadelphia | PA |
| FEITA CORPORATION | PHILADELPHIA | PA |
| FELINS MEAT PACKING | PHILADELPHIA | PA |
| FELS & COMPANY | PHILADELPHIA | PA |
| FELS AND COMPANY | PHILADELPHIA | PA |
| FELS JUNIOR HIGH SCHOOL | PHILADELPHIA | PA |
| FELS NAPTHA SOAP COMPANY, 73RD AND WOODLAND | PHILADELPHIA | PA |
| FELS SOAP COMPANY | PHILADELPHIA | PA |
| Fenestra Incorporated | Erie | PA |
| FERRO CORP | BIGLER | PA |
| FERRO CORP | ERIE | PA |
| FERRO CORP | HAZELTON | PA |
| FERROWS CHEMICAL COMPANY | PITTSBURGH | PA |
| FIBROUS GLASS CO | CARLISILE | PA |
| FIBROUS GLASS PRODUCTS | MOUNTAIN TOP | PA |
| Fidelity Bank Building | Philadelphia | PA |
| FIDELITY INSURANCE TRUST AND SAFETY DEPOSIT COMPANY | PHILADELPHIA | PA |
| FIDELITY MUTUAL LIFE ASSOCIATION | PHILADELPHIA | PA |
| FIDELITY MUTUAL LIFE BUILDING | PHILADELPHIA | PA |
| FIDELITY MUTUAL LIFE INSURANCE COMPANY | PHILADELPHIA | PA |
| Findlay Refractories Company | Washington | PA |
| Finnaren & Haley Paint | Conshohocken | PA |
| FIONESTA VALLEY CHEMICAL COMPANY | MAYBURG | PA |
| Fire Department Repair Shop | Philadelphia | PA |
| FIRE INCORPORATED | PITTSBURGH | PA |
| FIRESTONE PLASTICS PLANT | POTTSTOWN | PA |
| FIRESTONE TIRE & RUBBER | POTTSTOWN | PA |
| Firestone Tire & Rubber Co. | Philadelphia | PA |
| FIRESTONE TIRE AND RUBBER COMPANY | PHILADELPHIA | PA |
| FIRESTONE TIRE AND RUBBER COMPANY | POTTSTOWN | PA |
| FIRST FEDERAL SAVINGS & LOAN | SHARON | PA |
| First National Bank | Philadelphia | PA |
| FIRST NATIONAL BANK | ALLENTOWN | PA |
| FIRST NATIONAL BANK – HAMILTON STREET | ALLENTOWN | PA |
| FIRST NATIONAL BANK BUILDING | PITTSBURGH | PA |
| FIRST PENNSYLVANIA BANKING & TRUST – OPER BLDG | PHILADELPHIA | PA |
| First Presbyterian Church | Sharon | PA |
| First Presbyterian Church | Morrisville | PA |
| FIRST UNITED PRESBYTERIAN CHURCH | ALIQUIPPA | PA |
| Firth Sterling | Mckeesport | PA |
| FIRTH STERLING INC | PITTSBURGH | PA |
| FIRTH STERLING PLANT | MCKEESPORT | PA |
| Firth Sterling Steel Company | McKeesport | PA |
| FIRTH STERLING, INCOPRORATED | MCKEESPORT | PA |
| FIRTH STERLING, INCORPORATED | MCKEESPORT | PA |
| FIRTH-STERLING STEEL COMPANY | MCKEESPORT | PA |
| FIRTH-STERLING STEEL COMPANY | DEMMLER | PA |
| FISCHER PORTER | WARMINSTER | PA |
| FISHER BODY CORPORATION – Div. Of General Motors | FLEETWOOD | PA |
| Fisher Scientific Company | Pittsburgh | PA |
| Fitzpatrick Sheetmetal | Dubois | PA |
| FITZSIMMONS JUNIOR HIGH SCHOOL – 26TH & CUMBERLAND | PHILADELPHIA | PA |
| Flack Bros Inc | Harrisburg | PA |
| FLAGG, STANLEY G. & COMPANY | POTTSTOWN | PA |
| FLANNERY BOLT COMPANY | BRIDGEVILLE | PA |
| FLEETWOOD METAL BODY COMPANY | FLEETWOOD | PA |
| Fleischer Mills | Philadelphia | PA |
| FLINN & DREFFEIN | YORK | PA |
| FLOOR CHEMICAL CORP | PHILADELPHIA | PA |
| FLORIG EQUIPMENT CO | CONSHOHOCKEN | PA |
| FLORIG EQUIPMENT CO | CONSHOHECKEN | PA |
| Fmc Corporation | Colmar | PA |
| FMC CORPORATION, AMERICAN VISCOSE DIVISION | MEADVILLE | PA |
| FOLLANSBEE BROTHERS COMPANY | PITTSBURGH | PA |
| Folwell Bros. & John Bromley Sons | Philadelphia | PA |
| FOOD DISTRIBUTION CENTER | PHILADELPHIA | PA |
| Food Fair | Philadelphia | PA |
| FOOD FAIR STORE – WAREHOUSE | PHILADELPHIA | PA |
| FOOD FAIR STORES | PHILADELPHIA | PA |
| FOOD FAIR STORES WHSE – BOILER ROOM | PHILADELPHIA | PA |
| Foot Mineral Co. | Exton | PA |
| Foote Mineral | Exton | PA |
| FOOTE MINERAL COMPANY | EXTON | PA |
| FOR SCRAP | PHILADELPHIA | PA |
| FORBES STEEL COMPANY | CANONSBURG | PA |
| Ford and Kendig Company | Conshohocken | PA |
| FORD CITY FOUNDRY & MACHINE COMPANY | FORD CITY | PA |
| FORD CITY FOUNDRY & MACHINE COMPANY | GRAFF STATION | PA |
| Ford Motor Co. | Chester | PA |
| FORD MOTOR COMPANY | GLASSMERE | PA |
| FORD MOTOR COMPANY | PITTSBURGH | PA |
| Ford Pitt Hotel | Pittsburg | PA |
| FORGED STEEL WHEEL COMPANY | BUTLER | PA |
| FORREST LAUNDRY | PHILADELPHIA | PA |
| FORT BEDFORD INN | BEDFORD | PA |
| FORT CHERRY SCHOOL | MCDONALD | PA |
| FORT MARTIN POWER STATION | MAIDSVILLE | PA |
| Fort Miffin – Naval Ammunition Depot, Central Heating Plant | PHILADELPHIA | PA |
| FORT MIFFLIN | PHILADELPHIA | PA |
| FORT PITT HOTEL | PITTSBURG | PA |
| Fort Pitt Steel Casting | McKeesport | PA |
| FORT PITT STEEL CASTING CO | MCKEESPORT | PA |
| Fort Pitt Supply Company | Pittsburgh | PA |
| FORTY-FORT COLLIERY | BENNETT | PA |
| FOSECO INC. | MT. BRADDOCK | PA |
| Foster – Wheeler | Oil City | PA |
| FOSTER WHEELER CORPORATION | MOUNTAIN TOP | PA |
| FOSTER WHEELER CORPORATION | MOUNTAINTOP | PA |
| FOUNDERS HALL, RT. 322 | HERSHEY | PA |
| Four Corners Powerhouses. | Avoca | PA |
| FOUR STATES COAL COKE COMPANY | PITTSBURGH | PA |
| FOX RUN APARTMENTS | PHILADELPHIA | PA |
| FRANCIS BROTHERS & JELLETT | PHILADELPHIA | PA |
| FRANCIS BROTHERS & JELLETT, INCORPORATED | PHILADELPHIA | PA |
| FRANCISCO SUGAR COMPANY | PHILADELPHIA | PA |
| Frank & Sedar Dept. Store | Philadelphia | PA |
| FRANK FORD | PHILADELPHIA | PA |
| Frank Goodheart & Sons Inc. | Lancaster | PA |
| FRANK KNEELAND MACHINE COMPANY | PITTSBURGH | PA |
| Frank Roberts & Sons Inc | Punxsutawney | PA |
| FRANK ROMANO | PHILADELPHIA | PA |
| FRANK SAMUELS (CE MINERALS) | VALLEY FORGE | PA |
| Frankford Arsenal | Philadelphia | PA |
| FRANKFORD ARSENAL – FOURTH FLOOR REAR | PHILADELPHIA | PA |
| FRANKFORD ARSENAL, BUREAU OF ORDINANCE | PHILADELPHIA | PA |
| FRANKFORD HOSPITAL | PHILADELPHIA | PA |
| FRANKFORD JUNCTION | PHILADELPHIA | PA |
| FRANKFORD METAL TREATING | PHILADELPHIA | PA |
| FRANKFORD PLANT | PHILADELPHIA | PA |
| Frankfort High School | Philadelphia | PA |
| FRANKFORT METAL TREATING | PHILADELPHIA | PA |
| FRANKLIN BUILDING SUPPLY | NASHVILLE | PA |
| Franklin Lumber Co | New Alexandria | PA |
| FRANKLIN MANUFACTURING COMPANY | STONEBORO | PA |
| FRANKLIN MARSHALL COLLEGE | LANCASTER | PA |
| FRANKLIN MINT | PHILADELPHIA | PA |
| FRANKLIN MOTEL, 21ST AND SPRING GARDEN STS. | PHILADELPHIA | PA |
| FRANKLIN QUALITY REFINING COMPANY | FRANKLIN | PA |
| Franklin Smelting & Refining | Philadelphia | PA |
| FRANKLIN SMELTING AND REF | PHILADELPHIA | PA |
| Franklin Smelting Company | Concordville | PA |
| FRANKLIN SMELTINGG AND REF | PHILADELPHIA | PA |
| Franklin Steel Works | Franklin | PA |
| FRANKLIN SUGAR | PHILADELPHIA | PA |
| FRANKLIN SUGAR COMPANY | PHILADELPHIA | PA |
| FRANKLIN SUGAR REFINING COMPANY | PHILADELPHIA | PA |
| FRANKLIN TERRACE APARTMENTS | LANCASTER | PA |
| FRANKLIN WORKS | JOHNSTOWN | PA |
| FRANTZ DISTILLERS, INCORPORATED | BERLIN | PA |
| Frantz Heating & Roof Company | Reading | PA |
| FRAZEE LUMBER CO | UNIONTOWN | PA |
| FRAZIER SIMPLEX, INC. | WASHINGTON | PA |
| FREDERICK A. POTH | PHILADELPHIA | PA |
| FREEBROOK CORPORATION | KITTANNING | PA |
| Freedman Wholesale Lumber Co | Russellton | PA |
| Freedom High School | Bethlehem | PA |
| FREEDOM OIL WORKS COMPANY | FREEDOM | PA |
| Freedom-Valvoline Oil Company | Freedom | PA |
| FREEPORT BRICK CO | FREEPORT | PA |
| FREEPORT BRICK COMPANY | FREEPORT | PA |
| FREEPORT TERMINAL INC – LIQUID BULK TERMINAL | FREEPORT | PA |
| FREEPORT WATER WORKS COMPANY – WATER PURIFICATION PLANT | FREEPORT | PA |
| FREIGHT PITCALM PITTSBURGH, 28TH ST. POWERHOUSE, W. PHILADELPHIA STOCKYARD | PHILADELPHIA | PA |
| FREIGHT PITCALM PITTSBURGH, WOODLAND AVENUE | PHILADELPHIA | PA |
| FREIHOFER BAKING COMPANY | PHILADELPHIA | PA |
| FREIHOFER VIENNA BAKING COMPANY | PHILADELPHIA | PA |
| Frick Building | Pittsburg | PA |
| FRICK BUILDING | PITTSBURGH | PA |
| Friends School | Haverford | PA |
| FRISKIES PET CARE COMPANY, INCORPORATED | ALLENTOWN | PA |
| FROG SWITCH MANUFACTURING COMPANY | CARLISLE | PA |
| FROG SWITCH MFG C | CARLISLE | PA |
| FT. PITT BREWING COMPANY | SHARPSBURG | PA |
| FT. PITT HOTEL | PITTSBURGH | PA |
| FT. PITT MALLEABLE & GREY IRON COMPANY | MCKEES ROCKS | PA |
| FT. PITT MALLEABLE IRON COMPANY | MCKEES ROCKS | PA |
| G Ramsey & Sons | New Castle | PA |
| G. E. INDUSTRIAL TUBE PLANT | SCRANTON | PA |
| G. GARRETT & SONS | PHILADELPHIA | PA |
| G. W. Blabon Co. | Philadelphia | PA |
| G.A. Haupt, Jr. | Frackville | PA |
| G.A.F. CORPORATION INDUSTRIAL PROD DIVISION | ERIE | PA |
| G.B. MARKLE & COMPANY | GEDDA | PA |
| G.B. MARKLE & COMPANY | JEDDO | PA |
| G.B. MARKLE & COMPANY, HIGHLAND #5 COLL’Y | JEDDO | PA |
| G.B. MARKLE AND COMPANY | JEOLOLO | PA |
| G.B. MARKLE AND COMPANY, #4 COLLIERY | JEDDO | PA |
| G.E. Metropolitan Edison – Titus Station turbine | Edison | PA |
| G.K. GARRETT COMPANY | PHILADELPHIA | PA |
| G.S.A. | HARRISBURG | PA |
| G.W. ALLEN COMPANY | PHILADELPHIA | PA |
| G.W. CHILDS PUBLIC LEDGER BUILDING | PHILADELPHIA | PA |
| G.W. JOHNSON COMPANY | NEW CASTLE | PA |
| GAF (Ruberoid) | Erie | PA |
| GAF (Ruberoid) | Fullerton | PA |
| GAF CORPORATION | PHILADELPHIA | PA |
| GAF CORPORATION – 1139 LEHIGH AVENUE | FULLERTON | PA |
| GAF CORPORATION, 1139 LEHIGH AVE. | FULLERTON | PA |
| Gage Company | Titusville | PA |
| Gair Box | Philadelphia | PA |
| GALLERY CHEMICAL CORPORATION | CALLERY | PA |
| Garden Spot Jr High | New Holland | PA |
| GARDEN STATE TANNING COMP | FLEETWOOD | PA |
| GARFIELD JUNIOR HIGH SCHOOL | JOHNSTOWN | PA |
| GARLAND BROTHERS | PITTSBURGH | PA |
| GARLAND NUT AND RIVET COMPANY | WEST PITTSBURGH | PA |
| GARRICK THEATRE | PHILADELPHIA | PA |
| Gateway Center Building | Pittsburgh | PA |
| GATEWAY CENTER BUILDING #4 | PITTSBURGH | PA |
| GATEWAY II BUILDING | PITTSBURGH | PA |
| GAUTIER STEEL DEPARTMENT | JOHNSTOWN | PA |
| GAYLORD COLLIERY | PLYMOUTH | PA |
| GE | Erie | PA |
| GE Plant | Philadelphia | PA |
| Geare-Marston, Inc. | Philadelphia | PA |
| GEM MANUFACTURING COMPANY | PITTSBURGH | PA |
| GENERAL ACCEPTANCE CORPORATION – OFFICE BUILDING | ALLENTOWN | PA |
| General American Transport Corporation | Sharon | PA |
| GENERAL AMERICAN TRANSPORTATION CORPORATION | SHARON | PA |
| GENERAL CABLE COMPANY | GLENWILLARD | PA |
| GENERAL CARBIDE | GREENSBURG | PA |
| GENERAL CHEMCIAL COMPANY | MARCUS HOOK | PA |
| General Chemical | Marcus Hook | PA |
| GENERAL CHEMICAL COMPANY | NEWELL | PA |
| GENERAL CHEMICAL COMPANY | MARCUS HOOK | PA |
| GENERAL CHEMICAL COMPANY DIVISION, ALLIED CHEMICAL CORPORATION AND DYE CORPORATION | NEWELL | PA |
| GENERAL CHEMICAL COMPANY OF PENNSYLVANIA | PITTSBURGH | PA |
| GENERAL CHEMICAL COMPANY, DELAWARE WORKS | MARCUS HOOK | PA |
| GENERAL CHEMICAL DIVISION | NEWELL | PA |
| GENERAL CIGAR FACTORY | MOUNT CARMEL | PA |
| GENERAL COOPERAGE | PHILADELPHIA | PA |
| GENERAL DYNAMICS CORPORATION | PHILADELPHIA | PA |
| General Electric | Philadelphia | PA |
| General Electric | Erie | PA |
| GENERAL ELECTRIC | COURTNEY | PA |
| GENERAL ELECTRIC | WEST MIFFLIN | PA |
| GENERAL ELECTRIC – 30TH & WALNUT STREETS | PHILADELPHIA | PA |
| GENERAL ELECTRIC – PENNSYLVANIA ELECTRIC TURBINE REPAIR | PITTSBURGH | PA |
| GENERAL ELECTRIC – WAREHOUSE | PHILADELPHIA | PA |
| General Electric Co | Erie | PA |
| GENERAL ELECTRIC CO – BUILDING 64 | ERIE | PA |
| GENERAL ELECTRIC CO – VOLTAGE SWGR. DEPT. | PHILADELPHIA | PA |
| GENERAL ELECTRIC CO CAR | EAST STROUDSBURG | PA |
| General Electric Co. | Philadelphia | PA |
| GENERAL ELECTRIC CO. | ERIE | PA |
| General Electric Company | Eria | PA |
| General Electric Company | Erie | PA |
| GENERAL ELECTRIC COMPANY | PHILADELPHIA | PA |
| GENERAL ELECTRIC COMPANY | EAST STROUDSBURG | PA |
| GENERAL ELECTRIC COMPANY | KING OF PRUSSIA | PA |
| GENERAL ELECTRIC COMPANY | ALLENTOWN | PA |
| GENERAL ELECTRIC COMPANY – 3198 CHESTNUT STREET | PHILADELPHIA | PA |
| General Electric Company – Apparatus Pittsburgh Service Center | West Mifflin | PA |
| GENERAL ELECTRIC COMPANY – BRIDGEVILLE GLASS PLANT | BRIDGEVILLE | PA |
| GENERAL ELECTRIC COMPANY – BRIDGEVILLE GLASS PLANT – LAMP DEPARTMENT | BRIDGEVILLE | PA |
| General Electric Company – Erie Works Power Plant | Erie | PA |
| GENERAL ELECTRIC COMPANY – NEW KENSINGTON WORKS | NEW KENSINGTON | PA |
| GENERAL ELECTRIC COMPANY – POWER PLANT | ERIE | PA |
| GENERAL ELECTRIC COMPANY – POWER PLANT – TRANSPORTATION SYSTEMS DIVISION | ERIE | PA |
| General Electric Plant | King of Prussia | PA |
| General Electric Re-Entry Systems | PHILADELPHIA | PA |
| General Electric Switchgear Plant | PHILADELPHIA | PA |
| GENERAL ENGINEERING WORKS | PHILADELPHIA | PA |
| GENERAL ENGINEERING WORKS, INCORPORATED | PHILADELPHIA | PA |
| GENERAL HOSPITAL | EAST STROUDSBURG | PA |
| General Ionics Corporation | Bridgeville | PA |
| GENERAL MARKETING SERVICES | PITTSBURGH | PA |
| GENERAL MOTORS CORP. – FISHER BODY DIVISION | PITTSBURGH | PA |
| GENERAL MOTORS CORP. – W. MIFFLIN BORO | PITTSBURGH | PA |
| GENERAL REFR CORP | PHILADELPHIA | PA |
| General Refractories | Sproul | PA |
| General Refractories Co. | Philadelphia | PA |
| GENERAL SMELTING & REFINING COMPANY | PHILADELPHIA | PA |
| GENERAL SMELTING AND REFINI | PHILADELPHIA | PA |
| General Steel | Avonmore | PA |
| GENERAL STEEL CASTING | Eddystone | PA |
| GENERAL STEEL CASTINGS | BODYSTON | PA |
| GENERAL STEEL CASTINGS CORPORATION | EDDYSTONE | PA |
| GENERAL SUPPLY CO. | COPLAY | PA |
| GENERAL TEXTILE MILLS | PHILADELPHIA | PA |
| GENERAL TIRE & RUBBER CO – CHEMICALS & PLASTIC DIV. | JEANNETTE | PA |
| General Tire & Rubber Company | Jeanette | PA |
| Gene’s Garage | Philadelphia | PA |
| GENTEX CORPORATION | CARBONDALE | PA |
| Geo. F. Moilers Co. | Gettysburg | PA |
| GEO. SALL METALS | PHILADELPHIA | PA |
| GEORGE A. FULLER CONTRACTING COMPANY | PHILADELPHIA | PA |
| GEORGE A. SMITH AND COMPANY | PHILADELPHIA | PA |
| GEORGE E. FREDERICKS COMPANY | BETHAYRES | PA |
| GEORGE F. UBER COMPANY | PHILADELPHIA | PA |
| GEORGE HASLEY AND SONS | ALLEGHENY | PA |
| GEORGE I. BODINE, TRUSTEE | PHILADELPHIA | PA |
| GEORGE K. GARRETT COMPANY, INCORPORATED | PHILADELPHIA | PA |
| GEORGE M. NEWHALL ENGINEERING COMPANY | PHILADELPHIA | PA |
| GEORGE S. HARRIS | PHILADELPHIA | PA |
| GEORGE S. HARRIS & SONS | PHILADELPHIA | PA |
| GEORGE SALL METALS COMPANY | PHILADELPHIA | PA |
| GEORGE SCHOOL | BUCKS COUNTY | PA |
| GEORGE SCHOOL | GEORGE SCHOOL | PA |
| GEORGE SINGLETON | SCRANTON | PA |
| George V Hamilton Inc. | Mckees Rock | PA |
| GEORGE V. CRESSON | PHILADELPHIA | PA |
| GEORGE V. HAMILTON, INC. | MCKEES ROCKS | PA |
| GEORGE W. BLABON COMPANY | NICETOWN, PHILADELPHIA | PA |
| Georgia Pacific | Reading | PA |
| GEORGIA PACIFIC PULP & PAPER | READING | PA |
| GERACE HILL BOILER AND BUR | PHILADELPHIA | PA |
| GERACE WILLIAM | PHILADELPHIA | PA |
| GERARD TRUST BUILDING, 15TH AND MARKET STS. | PHILADELPHIA | PA |
| GERMAN HOSPITAL | PHILADELPHIA | PA |
| GERMANTOWN | PHILADELPHIA | PA |
| GERMANTOWN DISTRICT HIGH SCHOOL | PHILADELPHIA | PA |
| GERMANTOWN HOSPITAL | PHILADELPHIA | PA |
| GERMANTOWN JEWISH CENTER | PHILADELPHIA | PA |
| GERMANTOWN JUNCTION | PHILADELPHIA | PA |
| Germantown YMCA | Philadelphia | PA |
| GES; CIRCULATING FLUID BED PLANT | ERIE | PA |
| Gettysburg College Chapel | Gettysburg | PA |
| Gettysburg High School | Gettysburg | PA |
| GIANT PORTLAND CEMENT COMPANY | EGYPT | PA |
| GIBSON AND SONS, INCORPORATED | PHILADELPHIA | PA |
| Gibson Electric Co | Delmont | PA |
| GILBERT ASSOCIATES, INCORPORATED | READING | PA |
| GIMBELS STORE | PHILADELPHIA | PA |
| GIPSEY GROVE COLLIERY | DUNMORE | PA |
| GIRARD COAL COMPANY | MT. CARMEL | PA |
| GIRARD COAL COMPANY | PITTSTON | PA |
| Girard College | Philadelphia | PA |
| GIRARD ESTATE | PHILADELPHIA | PA |
| GIRARD ESTATE PEOPLES BANK | PHILADELPHIA | PA |
| GIRARD GOLLEGE | PHILADELPHIA | PA |
| GIRARD POINT | PHILADELPHIA | PA |
| GIRARD POINT LPG RECV & CAUSTIC REG | PHILADELPHIA | PA |
| GIRARD REFINERY | PHILADELPHIA | PA |
| GIRARD TRUST COMPANY | PHILADELPHIA | PA |
| GIRARD TRUST COMPANY BUILDING | PHILADELPHIA | PA |
| GIRARD TRUST COMPANY BUILDING – SOUTH PENN SQUARE | PHILADELPHIA | PA |
| GIRLS NORMAL SCHOOL | PHILADELPHIA | PA |
| Girton Mfg Co | Millville | PA |
| GLASGOW IRON COMPANY | POTTSTOWN | PA |
| GLASS CONTAINERS | KNOW | PA |
| Glass Containers Corp | Knox | PA |
| Glass Containers Corp | Marienville | PA |
| Glass Containers Corp | Parker | PA |
| Glass Containers Corporation | Parker | PA |
| Glassine Paper Co. | West Conshohocken | PA |
| GLASTIC CORP. | JEFFERSON | PA |
| GLATFELTER P H CO | SPRING GROVE | PA |
| Glatfelter P H Co. | Spring Grove | PA |
| GLATFELTER PAPER COMPANY | SPRING GROVE | PA |
| Glatfelter Paper Mill | Spring Grove | PA |
| Glatfelter PH Co. | Spring Grove | PA |
| Glen Alden Coal | Ashley | PA |
| GLEN ALDEN COAL CO – Staton Colliery | ASHLEY | PA |
| GLEN ALDEN COAL COMPANY | AUDENREID | PA |
| GLEN ALDEN COAL COMPANY | BUTTONWOOD | PA |
| GLEN ALDEN COAL COMPANY | NANTICOKE | PA |
| GLEN ALDEN COAL COMPANY | PLYMOUTH | PA |
| GLEN ALDEN COAL COMPANY | SOUTH WILKES BARRE | PA |
| GLEN ALDEN COAL COMPANY, MAXWELL COLLIERY | SCRANTON | PA |
| GLEN GERY SHADE BRICK | SHILLINGTON | PA |
| GLEN GERY SHALE BRICK CORPORATION | HARRISBURG | PA |
| GLEN GERY SHALE BRICK CORPORATION | WATSONTOWN | PA |
| GLEN GERY SHALE BRICK CORPORATION | EPHRATA | PA |
| GLEN SUMMIT | SPRING SIDING | PA |
| GLEN SUMMIT HOTEL AND LAND COMPANY | GLEN SUMMIT | PA |
| GLEN WILLOW ICE MANUFACTURING COMPANY, MANAYUNK | PHILADELPHIA | PA |
| Glenn M. Baker Heating & Plumbing | Huntingdon | PA |
| Glenshaw Glass Co | Glenshaw | PA |
| GLENSHAW GLASS CO INC | GLENSHAW | PA |
| GLIDDEN PROFESSIONAL PAINT – WAREHOUSE – CENTRE AVENUE | READING | PA |
| GLIDDEN-DURKEE | JOHNSTOWN | PA |
| Globe Automatic Sprinkler System | Philadelphia | PA |
| GLOBE DYE WORKS COMPANY | PHILADELPHIA | PA |
| GLOBE EYE WORKS | PHILADELPHIA | PA |
| GLOBE PLASTIC CO | CROYDON | PA |
| Globe Rubber Company | Philadelphia | PA |
| GLOBE TICKET CO | PHILADELPHIA | PA |
| GLP COMPANY | PHILADELPHIA | PA |
| GLYCO CHEMICAL DIVISION | WILLIAMSPORT | PA |
| GLYCO CHEMICALS DIVISION | WILLIAMSPORT | PA |
| Gnex Inc | Erie | PA |
| GOLD BOND BUILDING PRODUCTS | MILTON | PA |
| GOLDSMITH BUILDING | PHILADELPHIA | PA |
| GOLDSTEINS & SONS, INCORPORATED | PHILADELPHIA | PA |
| GOOD SHEPHERD ROMAN CATHOLIC PARISH | CAMP HILL | PA |
| GOOD SHEPHERD ROMAN CATHOLIC PARISH – CARLISLE PIKE | CAMP HILL | PA |
| Goodyear | Pittsburgh | PA |
| Goodyear | Grove City | PA |
| GOODYEAR TIRE AND RUBBER COMPANY | CONSHOHOCKEN | PA |
| GORDON STROBEL AND LAWREAU | PHILADELPHIA | PA |
| GOVERNOR MIFFLIN SENIOR HIGH SCHOOL – SOUTH WAVERLY STREET | SHILLINGTON | PA |
| GOVERNOR`S MANSION | HARRISBURG | PA |
| GPU NUCLEAR CORPORATION – THREE MILE ISLAND POWER PLANT | HARRISBURG | PA |
| Grace Mines | Cornwall | PA |
| Grace Mines | Morgantown | PA |
| GRAHAM FOUNDRY AND MACHINE COMPANY | MONONGAHELA | PA |
| GRAHAM JEAN | MALVERN | PA |
| Gram Asbestos Co | Erie | PA |
| GRAMHAM JEAN | MALVERN | PA |
| Grand Insulation | Philadelphia | PA |
| GRAND UNION STORE | MORRISVILLE | PA |
| GRANITE HOSIERY MILLS | SOUDERTON | PA |
| Grant Towers | Duquesne | PA |
| GRANTLEY ROAD, YORK COUTNY | YORK | PA |
| GRANVIEW HOSPITAL | SELLERSVILLE | PA |
| GRAPE PRODUCTS COMPANY | NORTH EAST | PA |
| GRASSELLI POWDER COMPANY | WYSIDE | PA |
| GRATERFORD STATE PENITENTIARY | GRATERFORD | PA |
| GRATZ & GILLESPIE SCHOOL – 17TH & LUZERNE | PHILADELPHIA | PA |
| GRATZ & GILLESPIE SCHOOL, 17TH & LUZERNE | PHILADELPHIA | PA |
| GRAYS FERRY COGENERATION PROJECT – POWER PRODUCTION FACILITY | PHILADELPHIA | PA |
| GRAYS FERRY ROAD AND CARPENTER STREET | PHILADELPHIA | PA |
| Great Lakes Steel | Pittsburgh | PA |
| GREAT SOUTHERN SHOPPERS MART | BRIDGEVILLE | PA |
| Greater Pittsburgh Airport | Pittsburgh | PA |
| Gree Inc | Erie | PA |
| GREEN BAG CEMENT | NEVILLE ISLAND | PA |
| Green Ridge Coal Company | Scranton | PA |
| GREEN SPRING COMPANY | PHILADELPHIA | PA |
| Green Tweed | North Wales | PA |
| GREENCASTLE PACKING CO. | GREENCASTLE | PA |
| Greengate Mall | Greensburg | PA |
| Greensburg Central Catholic High School | Greensburg | PA |
| GREENSBURG-CONNELLSVILLE COAL & COKE COMPANY | BURGETTSTOWN | PA |
| GREENVILLE | GLENWOOD | PA |
| GREENVILLE HOSPITAL | GREENVILLE | PA |
| GREENVILLE STEEL CAR COMPANY | GREENVILLE | PA |
| GREENVILLE STEEL CAR COMPANY PLANT | GREENVILLE | PA |
| GREENVILLE TUBE DIV. EMERSON | GREENVILLE | PA |
| GREENWICH COLLIERIES | BARNESBORO | PA |
| GREYHOUND BUS TERMINAL | PHILADELPHIA | PA |
| GRIFFIN ENAMUEL BRICK COMPANY | PEUKIOMEN | PA |
| GRIMME COMBUSTION INC DON | PHILADELPHIA | PA |
| GRIMMS | SHARON | PA |
| GRINNELL COMPANY, INCORPORATED | COLUMBIA | PA |
| Grinnell Corporation | Columbia | PA |
| GRISWOLD WORSTED COMPANY | DARBY | PA |
| GROCER’S SUGAR HOUSE | PHILADELPHIA | PA |
| GROVER CLEVELAND PUBLIC SCHOOL | PHILADELPHIA | PA |
| GROVER FARMS, INC | GROVER | PA |
| GUADACANAL (USS) | PHILADELPHIA | PA |
| GUARANTY SILK CORPORATION | NANTICOKE | PA |
| GUARDIAN ENCR & DEV CO | CARNEGIE | PA |
| Gulf (Chevron) Refinery, 1331 Unit | Philadelphia | PA |
| GULF OIL CO | PITTSBURGH | PA |
| Gulf Oil Company | Philadelphia | PA |
| GULF OIL CORP | GIRARD POINT | PA |
| GULF OIL CORP | PHILADELPHIA | PA |
| GULF OIL CORP – #4 BOILER HOUSE | PHILADELPHIA | PA |
| GULF OIL CORP – CHLOR BLDG #492 | GIRARD POINT | PA |
| GULF OIL CORP – COOL HOUSE #491 & CHLOR BLDG #492 | GIRARD POINT | PA |
| GULF OIL CORP – COOLING WATER PUMP HOUSE #491 | GIRARD POINT | PA |
| GULF OIL CORP – COOLING WATER PUMP HOUSE #491 | PHILADELPHIA | PA |
| GULF OIL CORP – GATE #24 | GIRARD POINT | PA |
| GULF OIL CORP – GATE #24 | PHILADELPHIA | PA |
| GULF OIL CORP – GATE 24 PENROSE AVE. AT LANIER – GIRARD POINT | PHILADELPHIA | PA |
| GULF OIL CORP – GIRARD POINT | PHILADELPHIA | PA |
| GULF OIL CORP – GIRARD POINT REFINERY | PHILADELPHIA | PA |
| GULF OIL CORP – GIRARD POINT REFINERY – GATE #24 | PHILADELPHIA | PA |
| GULF OIL CORP – GIRARD POINT REFINERY – SULPHUR UNIT | PHILADELPHIA | PA |
| GULF OIL CORP – NUMBER 3 BOILER HOUSE | PHILADELPHIA | PA |
| GULF OIL CORP – PHILADELPHIA REFINERY | PHILADELPHIA | PA |
| GULF OIL CORP – PHILADELPHIA REFINERY – #4 BOILER HOUSE AREA | PHILADELPHIA | PA |
| GULF OIL CORP – PHILADELPHIA REFINERY – 15# AND 200 LB. STEAM REPLACEMENT | PHILADELPHIA | PA |
| GULF OIL CORP – PHILADELPHIA REFINERY – GATE NO. 24 | PHILADELPHIA | PA |
| GULF OIL CORP – SULPHUR UNIT PHILADELPHIA REFINERY | PHILADELPHIA | PA |
| GULF OIL CORP – VISA BREAKER UNIT | PHILADELPHIA | PA |
| Gulf Oil Corp. Girard Point | Philadelphia | PA |
| Gulf Oil Corporation | Girard Point | PA |
| Gulf Oil Corporation | Philadelphia | PA |
| Gulf Oil Corporation | Pittsburgh | PA |
| Gulf Oil Refinery | Pittsburgh | PA |
| GULF OIL REFINERY | PHILADELPHIA | PA |
| Gulf Refinery | Philadelphia | PA |
| Gulf Refining Company | Girard Point | PA |
| GULF REFINING COMPANY | PITTSBURGH | PA |
| GULF REFINING COMPANY (Subsid. Of Gulf Oil) | NEVILLE ISLAND | PA |
| GULF RESEARCH & DEVELOPMENT | CHESWICK | PA |
| GULF RESEARCH & DEVELOPMENT | HARMARVILLE | PA |
| GULF RESEARCH & DEVELOPMENT | PITTSBURGH | PA |
| GULF RESEARCH & DEVELOPMENT CO | PITTSBURGH | PA |
| GULF RESEARCH AND DEVELOPMENT COMPANY | HARMARVILLE | PA |
| GULF RESEARCH AND DEVELOPMENT COMPANY | PITTSBURGH | PA |
| GULF RESEARCH AND DEVELOPMENT COMPANY LABORATORY | CHESWICK | PA |
| GULPH WOOLEN MILLS | GULPH | PA |
| GUN PLANT #269 | PHILADELPHIA | PA |
| H A Diffenbach | Philadelphia | PA |
| H H Robertson Co | Ambridge | PA |
| H MILLER SPRING & MFG CO | PITTSBURGH | PA |
| H MILLER SPRING AND MFG CO | PITTSBURGH | PA |
| H. Blinderman & Son | Hellertown | PA |
| H. Daroff and Sons | Philadelphia | PA |
| H. H. HEINZ LAB. | PITTSBURGH | PA |
| H. H. ROBERTSON COMPANY | AMBRIDGE | PA |
| H. J. HEINZ CO – MECHANICAL STOCK ROOM | PITTSBURGH | PA |
| H. J. HEINZ CO – PGH PLUMBING DEPARTMENT | PITTSBURGH | PA |
| H. J. HEINZ CO – PITTSBURGH PLUMBING DEPT | PITTSBURGH | PA |
| H. J. HEINZ CO – PITTSBURGH PLUMBING DEPT – DOCK NO 5 | PITTSBURGH | PA |
| H. J. HEINZ CO – PLUMBING DEPARTMENT | PITTSBURGH | PA |
| H. J. HEINZ CO – PLUMBING DEPARTMENT – DOCK NO. 5 | PITTSBURGH | PA |
| H. J. HEINZ CO – STOCK ROOM | PITTSBURGH | PA |
| H. J. HINES | PITTSBURGH | PA |
| H. J. HINES – RESEARCH LABS. | PITTSBURGH | PA |
| H. JULIUS KLINGLER AND COMPANY | BUTLER | PA |
| H. KOPPERS COMPANY | NEW CASTLE | PA |
| H. KOPPERS COMPANY | PITTSBURGH | PA |
| H. O. Price Co. | Philadelphia | PA |
| H. WESTHOFF- FLORIST | HOFFMAN STA. | PA |
| H.C. FRICK COKE COMPANY | PITTSBURGH | PA |
| H.C. FRICK COKE COMPANY | MONARCH | PA |
| H.C. FRICK COKE COMPANY | ROWES RUN STATION | PA |
| H.C. FRICK COKE COMPANY | LAMBERT | PA |
| H.C. FRICK COKE COMPANY | RONCO | PA |
| H.C. FRICK COKE COMPANY | MONMOUTH | PA |
| H.C. FRICK COKE COMPANY | MT. PLEASANT | PA |
| H.C. FRICK COKE COMPANY | UNITED STA | PA |
| H.C. FRICK COKE COMPANY | WESTMORELAND COUNTY | PA |
| H.C. FRICK COKE COMPANY | MT. PLEASANT STATION | PA |
| H.C. FRICK COKE COMPANY | ROWES RUN | PA |
| H.C. FRICK COKE COMPANY | UNION STATION | PA |
| H.C. FRICK COKE COMPANY | BROWNFIELD | PA |
| H.C. FRICK COKE COMPANY | CALUMET | PA |
| H.C. FRICK COKE COMPANY | COLBERS MINE | PA |
| H.C. FRICK COKE COMPANY | DEARTH MINES | PA |
| H.C. FRICK COKE COMPANY | LEITH | PA |
| H.C. FRICK COKE COMPANY | PHILLIPS MINE | PA |
| H.C. FRICK COKE COMPANY | TROTTER | PA |
| H.C. FRICK COKE COMPANY | WALNUT HILL | PA |
| H.C. FRICK COKE COMPANY | YORK RUN | PA |
| H.C. FRICK COKE COMPANY | BUTE STATION | PA |
| H.C. Price Company | Philadelphia | PA |
| H.D. JUSTI DIVISION | PHILADELPHIA | PA |
| H.E. BROSIUS | KITTANNING | PA |
| H.E. COLLIERY | BENNETT | PA |
| H.F. WATSON | ERIE | PA |
| H.H. Chrowder Company | Allentown | PA |
| H.H. CURRY COMPANY | PITTSBURGH | PA |
| H.H. ROBERTSON COMPANY | PITTSBURGH | PA |
| H.H. ROBERTSON COMPANY | AMBRIDGE | PA |
| H.J. HEINZ | PITTSBURGH | PA |
| H.J. HEINZ AND COMPANY | PITTSBURGH | PA |
| H.J. HEINZ CO | CHAMBERSBURG | PA |
| H.J. HEINZ COMPANY | CHAMBERSBURG | PA |
| H.J. HEINZ COMPANY | PITTSBURGH | PA |
| H.J. HEINZ COMPANY | ALLEGHENY | PA |
| H.K. CRIMMING TRADESMAN GRAIN ELEVATOR AND STORAGE COMPANY | PHILADELPHIA | PA |
| H.K. CUMMINGS | PHILADELPHIA | PA |
| H.K. HORTER AND COMPANY | PITTSBURGH | PA |
| H.K. PORTER AND COMPANY | PITTSBURGH | PA |
| H.K. PORTER BUILDING – GRANT STREET | PITTSBURGH | PA |
| H.K. PORTER COMPANY | PITTSBURGH | PA |
| H.K. PORTER, GRANT AND 6TH STS. | PITTSBURGH | PA |
| H.L. EDWARDS AND COMPANY | PHILADELPHIA | PA |
| H.P. KINSEY | EASTON | PA |
| H.R. Curry | Sharpsburg | PA |
| H.R. CURRY CO. | SHARPSBURG | PA |
| H.R. CURRY COMPANY, INCORPORATED | PITTSBURGH | PA |
| H.T. WATSON COMPANY | ERIE | PA |
| H.W. BUTTERWORTH AND SONS | PHILADELPHIA | PA |
| HADDEN STEEL COMPANY | CUPOLA | PA |
| HAFLEIGH AND COMPANY | PHILADELPHIA | PA |
| HAHN LOUIS & SONS | PITTSBURGH | PA |
| HAHN LOUIS AND SONS | PITTSBURGH | PA |
| Hahnemann Hospital | Philadelphia | PA |
| HAHNEMANN HOSPITAL – BROAD & VINE STREETS | PHILADELPHIA | PA |
| Hahnemann Medical College | Philadelphia | PA |
| HAINSWORTH STEEL COMPANY | PITTSBURGH | PA |
| HAJOCA BUILDING | PHILADELPHIA | PA |
| HAJOCA BUILDING – GROUND FLOOR | PHILADELPHIA | PA |
| HAJOCA CORP | LANSDALE | PA |
| HAJOCA CORP | READING | PA |
| HALE BUILDING | PHILADELPHIA | PA |
| HALL AND GARRISON | PHILADELPHIA | PA |
| HALLMOR CO. | BETHEL PARK | PA |
| Halstead Metal Products, Inc. | Zelienople | PA |
| HALTENBACK AND STEPHENS | ALLENTOWN | PA |
| HAMILTON CONSTRUCTION | PHILADELPHIA | PA |
| Hamilton George V Inc | Mckees Rock | PA |
| HAMILTON WATCH COMPANY | LANCASTER | PA |
| HAMMERMILL PAPER | LOCK HAVEN | PA |
| Hammermill Paper Co | Lock Haven | PA |
| HAMMERMILL PAPER CO. | ERIE | PA |
| Hammermill Paper Company | Lock Haven | PA |
| Hammermill Paper Company | Erie | PA |
| HAMMERMILL PAPER COMPANY (k/n/a International Paper) | ERIE | PA |
| Hammermill Paper Mill | Erie | PA |
| HAMOT HOSPITAL | ERIE | PA |
| Hamot Medical Center | Erie | PA |
| HAMPTON BOILER PLANT | SCRANTON | PA |
| HAMPTON MINES | SCRANTON | PA |
| HANDSHUH JOE BUILDER | ROSLYN | PA |
| HANDY & HARMAN TUBE COMPANY | NORRISTOWN | PA |
| HANNASTOWN PLANT/JAMISON COAL AND COKE | HANNASTOWN | PA |
| HANOVER POWER COMPANY – POWER PLANT | HANOVER | PA |
| HAPPENSTALL COMPANY | PITTSBURGH | PA |
| HAPPY DAY LAUNDRY | PITTSBURGH | PA |
| HARBISON WALKER | WEST MIFFLIN | PA |
| HARBISON WALKER | PITTSBURGH | PA |
| Harbison Walker Refactories Co. | Pittsburgh | PA |
| HARBISON WALKER REFRACTORIES | MT. UNION | PA |
| HARBISON WALKER REFRACTORIES COMPANY | CHESTER, DELAWARE COUNTY | PA |
| HARBISON-WALKER REFR. CO. | PITTSBURGH | PA |
| HARBISON-WALKER REFRACTORIES CO | PITTSBURG | PA |
| HARBISON-WALKER REFRACTORIES COMPANY | PITTSBURGH | PA |
| HARBISON-WALKER REFRACTORIES COMPANY | WOODLAND | PA |
| HARBISON-WALKER REFRACTORIES COMPANY | MT. UNION | PA |
| Harbor Steel | New Castle | PA |
| HARCAST CORPORATION | GLENOLDEN | PA |
| HARDESTY INDUSTRIES | PHILADELPHIA | PA |
| HARDING AVE. JR. HIGH SCHOOL | ALIQUIPPA | PA |
| HARDINGE CO | YORK | PA |
| HARDWARE & INDUSTRIAL TOOL | PHILADELPHIA | PA |
| HARDWICK AND MAGEE COMPANY | PHILADELPHIA | PA |
| HARLEIGH BROOKWOOD COAL COMPANY | MAHANOY PLANE | PA |
| HARLEIGH BROOKWOOD COAL COMPANY | POTTSVILLE | PA |
| Harleigh-Brookwood Colleries | PA | |
| HARMAR COAL | HARMARVILLE | PA |
| HARRISBURG AIRPORT | HARRISBURG | PA |
| HARRISBURG FOUNDRY & MACHINE COMPANY | EASTON | PA |
| Harrisburg Hospital | Harrisburg | PA |
| HARRISBURG LIGHT AND POWER – HYDROELECTRIC PLANT | HARRISBURG | PA |
| HARRISBURG STATE HOSPITAL – BREECHING BOILER HOUSE | HARRISBURG | PA |
| Harrisburg Steel | Harrisburg | PA |
| HARRISBURG WATER WORKS – MUNICIPAL PLANT | HARRISBURG | PA |
| HARRISON BROTHERS | PHILADELPHIA | PA |
| HARRISON BUILDING | PHILADELPHIA | PA |
| HARRISON, FRAZIER & COMPANY | PHILADELPHIA | PA |
| HARRISON, HAVEMEYER & COMPANY | PHILADELPHIA | PA |
| HARRISON, HAVEMEYER & COMPANY, FRANKLIN REFINERY | PHILADELPHIA | PA |
| HARRY A. PROCK CABINET COMPANY | GLENSIDE | PA |
| HARRY C OLSON INC | MT LEBANON | PA |
| Harry Ellenberger Lbr Co | Chicora | PA |
| HARRY ROMAN | PITTSBURGH | PA |
| Harshaw, Fuller, and Goodwin | Philadelphia | PA |
| HARTMAN STEEL COMPANY | BEAVER FALLS | PA |
| HARVEY AND COLLINS | AUSTIN | PA |
| HARWOOD | HAZLETON | PENNSYLVANIA |
| Harwood Electric Co. | Harwood | PA |
| HARWOOD ELECTRIC COMPANY – POWER PLANT | HARWOOD | PA |
| HARWOOD ELECTRIC COMPANY – STEAM PLANT | HARWOOD | PA |
| HASELTON SEWAGE | WEST HAZELTON | PA |
| Hatboro Plumbing & Heating | Hatboro | PA |
| Hatfield Power Station | Masontown | PA |
| Hatfield Power Station | Hatfield | PA |
| HATFIELD POWER STATION – UNITS 1 & 2 | MASONTOWN | PA |
| HATFIELD’S FERRY POWER STATION | MASONTOWN | PA |
| HAUTO | NESQUEHONING | PENNSYLVANIA |
| Haverford District High School | Haverford | PA |
| Haverford High School | Haverford | PA |
| HAVERFORD STATE MENTAL HOSPITAL | HAVERFORD | PA |
| Hawk Run Acid Mine Water Treatment Plant | Hawk Run | PA |
| Hays Army Depot | Pittsburgh | PA |
| HAZARD MANUFACTURING COMPANY | WILKES BARRE | PA |
| Hazel Atlas Glass Co. | Washington | PA |
| HAZELTON BRICK CO | HAZELTON | PA |
| Hazelton Brick Co. | Hazelton | PA |
| Hazelton Plumbing Heating & Supply Company | Hazelton | PA |
| Hazelton Sewage Plant | Hazelton | PA |
| HAZELTON SEWAGE TREATMENT | HAZELTON | PA |
| HAZELWOOD BYPRODUCTS – #2 FRACTIONATING COLUMN | PITTSBURGH | PA |
| HAZELWOOD PLT BATT #2 | PITTSBURGH | PA |
| HAZLE MOUNTAIN COAL COMPANY | CONYNGHAM | PA |
| HAZLETON AUTHORITY (a/k/a Duplan Corp.) | HAZLETON | PA |
| HAZLETON ELECTRIC LIGHT AND POWER COMPANY – POWER PLANT | HAZLETON | PA |
| HAZLETON WATER COMPANY – HUDSONDALE PLANT | HUDSONDALE | PA |
| HBG | Enola | PA |
| HEALTH CENTER #9 – EAST CHELTEN AVENUE | PHILADELPHIA | PA |
| HEATHERINGTON PLANT | FOLCROFT | PA |
| HEEREN BROTHERS AND COMPANY | PITTSBURGH | PA |
| HEIDELBERG COLLIERY | AVOCA | PA |
| HEINTZ DIVISION OF KELSEY HAYES COMPANY | PHILADELPHIA | PA |
| HEINTZ MANUFACTURING COMPANY | PHILADELPHIA | PA |
| HEINZ U.S.A. | PITTSBURGH | PA |
| HELFENSTEIN, LEWIS AND GREEN | PHILADELPHIA | PA |
| HELLEN MILLS | BROCKPORT, ELK COUNTY | PA |
| HELLWIG SILK DYING CO – Delaware Ave & Howell St. | WISSINOMING / PHILADELPHIA | PA |
| HENDEL HAT COMPANY | READING | PA |
| Henderson Sugar Refinery | Philadelphia | PA |
| HENDRICK MANUFACTURING COMPANY | CARBONDALE | PA |
| HENRY CLAY FURNACE | CHICKIES | PA |
| HENRY COLLIERY | WILKES BARRE | PA |
| Henry Disston & Sons | Tacony | PA |
| HENRY DISSTON & SONS, INC. | PHILADELPHIA | PA |
| HENRY LAUDENSLAGER | HARRISBURG | PA |
| HENRY MCKEEN AND COMPANY | LEHIGH MILLS SOUTH EASTON | PA |
| HENRY PHIPPS CENTRAL POWER PLANT | PITTSBURGH | PA |
| HENRY PHIPPS MUTUAL TRAINING SCHOOL | ALLEGHENY | PA |
| HEPPENSTALL | PITTSBURGH | PA |
| HEPPENSTALL FORGE AND KNIFE COMPANY | PITTSBURGH | PA |
| HEPPENSTALL OF PITTSBURGH | PITTSBURGH | PA |
| HEPPENSTALL-EDDYSTONE CORPORATION | EDDYSTONE | PA |
| Hercules Cement Company | Stockertown | PA |
| Hercules Cement Corp. | Hercules | PA |
| Hercules Cement Corp. | Stokertown | PA |
| HERCULES CEMENT CORPORATION | STOCKERTOWN | PA |
| Hercules Picco Resins | W. Elizabeth | PA |
| HERCULES PLANT | DONORA | PA |
| HERCULES POWDER CO – HIGGINS PLANT | PHILADELPHIA | PA |
| Herman Goldner Co. (Quaker Rubber Co.) | Philadelphia | PA |
| HERR GAS & OIL | SHAMOKIN | PA |
| HERRIS ISLAND | PITTSBURGH | PA |
| Herron Hill Pumping Station | Pittsburg | PA |
| HERRS POTATO CHIPS, INCORPORATED | NOTTINGHAM | PA |
| HERSHEY CHOCOLATE COMPANY | BERNVILLE | PA |
| HERSHEY CHOCOLATE CORPORATION | HERSHEY | PA |
| Hershey Chocolate Corporation, Lobby | HERSHEY | PA |
| HERSHEY CHOCOLATE USA | HERSHEY | PA |
| Hershey Food Company | Hershey | PA |
| Hershey Foods Corp | Hershey | PA |
| HERSHEY FOODS CORPORATION | HERSHEY | PA |
| Hershey Medical Center, Hospital | Hershey | PA |
| HERSHEY STATE POLICE TRAINING BARRI | HERSHEY | PA |
| Hertz Supply Company Inc | Allentown | PA |
| HESS BROTHERS WAREHOUSE | ALLENTOWN | PA |
| HESS DEPARTMENT STORE | LANCASTER | PA |
| HESS DEPARTMENT STORE, HARRISBURG | LANCASTER | PA |
| HESS, INCORPORATED | SCRANTON | PA |
| Heston High School | Philadelphia | PA |
| HESTONVILLE MANTUA & FAIRMOUNT PASSENGER RAILROAD COMPANY | PHILADELPHIA | PA |
| HETRICK AND WILSON | INDIANA | PA |
| Hewlett Packard | Avendale | PA |
| HEYL & PATTERSON, INCORPORATED | PITTSBURGH | PA |
| HEYL AND PATTERSON | PITTSBURGH | PA |
| Heyl Physicians Supply Co | Erie | PA |
| HI LINE STEEL BOILER | MT. CARMEL | PA |
| HIBBARD-RODMAN-ELY SAFE COMPANY | PLAINFIELD | PA |
| HICKORY RIDGE COLLIERY | SHAMOKIN | PA |
| HICKORY SWAMP COLLIERY | SHAMOKIN | PA |
| HIGHLAND BREWING COMPANY | PITTSBURGH | PA |
| HIGHLAND COLLIERY #5 | JEDDO | PA |
| HIGHWAY MATERIALS | BRIDGEPORT | PA |
| HILLSIDE COAL AND IRON COMPANY | MAYFIELD | PA |
| HILLSIDE COAL AND IRON COMPANY | PITTSTON | PA |
| HILTON HOTEL | LANCASTER | PA |
| HILTON HOTEL | MCKEES ROCKS | PA |
| HILTON HOTEL – EMPIRE BLDG – GATEWAY NO 3 | MCKEES ROCKS | PA |
| HINCHLIFFE & KEENER | INDIANA CITY | PA |
| Hinchliffe & Keener Inc. | Pittsburgh | PA |
| Hinckliffe Keener | Pittsburgh | PA |
| HIRAM SWANK & SONS | JOHNSTOWN | PA |
| Hiram Swank’s Sons | Johnstown | PA |
| Hiram Swank’s Sons | Irovone | PA |
| Hk Porter Company | Pittsburgh | PA |
| Hoetetters Supply Company | York | PA |
| HOFFMAN BROS | PUNXSUTAWNEY | PA |
| Hog Island Shipyard | Philadelphia | PA |
| Holiday Inn | Philadelphia | PA |
| Holland Furnace | Delaware County | PA |
| Holland Furnace Company | PA | |
| HOLLENBACH COLLIERY #2 | WILKES BARRE | PA |
| HOLLENBACH COLLIERY #5 | WILKES BARRE | PA |
| HOLMESBURG, TACONY AND FRANKFORD ELECTRIC RAILWAY COMPANY – POWER PLANT | PHILADELPHIA | PA |
| HOLTWOOD | HOLTWOOD | PENNSYLVANIA |
| Holy Ghost Convent and School | Pittsburgh | PA |
| Holy Redeemer Hospital | Philadelphia | PA |
| HOLY REDEEMER HOSPITAL | MEADOWBROOK | PA |
| HOME ELECTRIC LIGHT AND STEAM HEATING COMPANY – POWER PLANT | TYRONE | PA |
| HOMEOPATHIC HOSPITAL | PITTSBURGH | PA |
| HOMEOPATHIC HOSPITAL FOR THE INSANE | EAST ALLENTOWN | PA |
| HOMEOPATHIC STATE HOSPITAL | LEHIGH COUNTY | PA |
| HOMEOPATHIC STATE HOSPITAL FOR THE INSANE | HANOVER TOWNSHIP | PA |
| HOMER CITY | HOMER CITY | PENNSYLVANIA |
| HOMER CITY – SAM PACE | CORAL | PA |
| Homer City Power Plant | Homer City | PA |
| Homer City Power Station | Indiana County | PA |
| HOMER CITY POWER STATION | HOMER | PA |
| HOMER CITY POWERHOUSE | HOMER CITY | PA |
| Homer City Station – Power Plant | HOMER CITY | PA |
| HOMESTEAD BOROUGH MUNICIPAL WATER WORKS | HOMESTEAD | PA |
| HOMESTEAD HIGHLAND STREET RAILWAY COMPANY | HOMESTEAD | PA |
| HOMESTEAD INDUSTRIES | CORAOPOLIS | PA |
| HOMESTEAD STEEL WORKS | MUNHALL | PA |
| HOMESTEAD STEEL WORKS | PITTSBURGH | PA |
| HOMESTEAD WORKS | HOMESTEAD | PA |
| HOMESTEAD WORKS | MUNHALL | PA |
| Homestead Works US Steel | Homestead | PA |
| HONEY BROOK COLLIERY #5 | AUDENRIED | PA |
| HONEYWELL | FORT WASHINGTON | PA |
| HONEYWELL, INCORPORATED | EMLENTON | PA |
| HONEYWELL, INCORPORATED | T SMETHPORT | PA |
| HOOD, BONBRIGHT AND COMPANY | PHILADELPHIA | PA |
| HOOPES AND TOWNSEND | FT. WASHINGTON | PA |
| HOOPES AND TOWNSEND COMPANY | FT. WASHINGTON | PA |
| Hopeman Borthers | Chester | PA |
| HOPKINSON HOUSE APARTMENTS | PHILADELPHIA | PA |
| Hopper Paper Company | Reading | PA |
| HORATIO B. HACKETT SCHOOL – EAST YORK STREET | PHILADELPHIA | PA |
| Horlacher Brewing Company | Allentown | PA |
| HORNER SCHOOL BUILDING | WILKINSBURG | PA |
| HORSEHEAD INDUSTRIES | MONACA | PA |
| Hosletter Supply Company | York | PA |
| HOSPITAL FOR THE INSANE | RETREAT | PA |
| HOSPITALITY MOTOR INN | PITTSBURGH | PA |
| HOST MOTEL | LANCASTER | PA |
| HOSTETTER SUPPLY CO. | YORK | PA |
| HOTEL LAFAYETTE | PHILADELPHIA | PA |
| HOUDRY PROCESS CORP. | LINWOOD | PA |
| Houdry Processing Corp. | Linwood | PA |
| HOUSE OF CORRECTION | PHILADELPHIA | PA |
| HOUSE OF GOOD SHEPARD | READING | PA |
| HOUSE OF THE GOOD SHEPHERD | PHILADELPHIA | PA |
| HOWARD AXLE PLANT | HOMESTEAD | PA |
| HOWARD REED | PHILADELPHIA | PA |
| HOWE AND POLK | DANVILLE | PA |
| HOWE AND SAMUEL | DANVILLE | PA |
| HOWE SOUND COMPANY | LANCASTER | PA |
| HOWE, BROWN & COMPANY | PITTSBURGH | PA |
| HOWMET CORP | LANCATER | PA |
| HOWMET CORP | LANCASTER | PA |
| HOWMET CORP. | LANCASTER | PA |
| HOWMET CORPORATION | LANCASTER | PA |
| HUBBARD TOOL DIVISION | PITTSBURGH | PA |
| Hubbs & Howe Co | Erie | PA |
| HUCHINSON AND GUNTER PLANT | GREENSBURG | PA |
| HUDSON COAL COMPANY | SCRANTON | PA |
| HUDSON COAL COMPANY | OLYPHANT | PA |
| HUDSON COAL COMPANY | CARBONDALE | PA |
| Hudwood Irwin Company, Inc. | Huntingdon | PA |
| HUFFMAN INDUSTRIES | SINKING SPRINGS | PA |
| HUGH MCINNES REBECCA PAPER MILL | BRIDGEPORT | PA |
| HUGHES AND GAUTHORP COMPANY | PITTSBURGH | PA |
| HUGHES AND GAWTHROP | PITTSBURGH | PA |
| HUGHES AND PATTERSON | PHILADELPHIA | PA |
| HUGUS AND HACKE | PITTSBURGH | PA |
| Hummelstown Water Supply | Harrisburg | PA |
| HUNLOCK CREEK | LUZERNE COUNTY | PA |
| Hunlock Creek Powerhouse | Hunlock Creek | PA |
| Hunter Manufacturing | Levittown | PA |
| Hunter Saw & Machine | Lawrenceville | PA |
| HUNTING PARK AVENUE PLANT – MANUFACTURING PLANT | PHILADELPHIA | PA |
| HUSSEY BUILDING | PITTSBURGH | PA |
| Hussey Met | Leetsdale | PA |
| Hussey Metals Company | Leetsdale | PA |
| HUTCHINSON STREET STATION – COAL PLANT | PHILADELPHIA | PA |
| HYDE HEATING CO | PITTSBURGH | PA |
| HYDE PARK GAS COMPANY – GAS PLANT | SCRANTON | PA |
| HYDRIL CO. | ROCHESTER | PA |
| Hydro-Blast Corporation | Burnham | PA |
| Hydro-Blast Corporation | Danville | PA |
| Hydro-Blast Corporation | Erie | PA |
| Hydro-Blast Corporation | Franklin | PA |
| Hydro-Blast Corporation | Philadelphia | PA |
| Hydro-Blast Corporation | Waynesboro | PA |
| HYGEIA ICE COMPANY | PHILADELPHIA | PA |
| HYGRADE FOOD PRODUCTS | PHILADELPHIA | PA |
| HYGRADE FOODS | PHILADELPHIA | PA |
| HYMAN BRODSKY & SON | PHILADELPHIA | PA |
| I.T.E. Circuit Breaker Co. | Philadelphia | PA |
| I.T.E. CIRCUIT BREAKER CO. | COLMAR | PA |
| IBERIA SUGAR COOPERATIVE, INCORPORATED | NEW IBERIA | PA |
| IBM BUIDLING | PITTSBURGH | PA |
| IBM BUILDING, 17TH AND MARKET STS. | PHILADELPHIA | PA |
| IBM BUILDING, BLVD. OF THE ALLIES | PITTSBURGH | PA |
| IBM BUILDING, STANWIX ST. | PITTSBURGH | PA |
| IBM OFFICE BLDG | PITTSBURGH | PA |
| ILLINOIS STEEL COMPANY | PITTSBURGH | PA |
| ILLINOIS ZINC COMPANY | PITTSBURGH | PA |
| IMAGINING SYSTEMS | LATROBE | PA |
| IMMACULATE CONCEPTION CATHEDRAL | PHILADELPHIA | PA |
| Immaculate Conception School | Lock Haven | PA |
| IMPERIAL LEATHER COMPANY | ALLEGHENY | PA |
| IMPERIAL TYPE METALS | PHILADELPHIA | PA |
| IMPERVIOUS VARNISH COMPANY | ROCHESTER | PA |
| INDEPENDENCE HALL – 6TH & CHESTNUT STREETS | PHILADELPHIA | PA |
| INDEPENDENT BREWING COMPANY | ALLEGHENY | PA |
| INDEPENDENT BREWING COMPANY OF PITTSBURGH | PITTSBURGH | PA |
| INDEPENDENT BRIDGE COMPANY | PITTSBURGH | PA |
| INDEPENDENT MANUFACTURING COMPANY | PHILADELPHIA | PA |
| INDIAN AFFAIRS BUILDING – CHESTNUT STREET | PHILADELPHIA | PA |
| INDIANA COLD STORAGE AND ICE COMPANY | INDIANA | PA |
| INDIANA COUNTY RAILWAYS COMPANY | HOMER | PA |
| INDIANA COUNTY RAILWAYS COMPANY | PUNXSUTAWNEY | PA |
| INDIANA ERIE COMPANY | INDIANA | PA |
| INDIANA HOSPITAL | INDIANA | PA |
| INDIANA PROVISION COMPANY | INDIANA | PA |
| Industrial Air Conditioning | Philadelphia | PA |
| INDUSTRIAL COLD STORAGE AND WAREHOUSE COMPANY | PHILADELPHIA | PA |
| INDUSTRIAL DIV. WAREHOUSE | PITTSBURGH | PA |
| INDUSTRIAL EQUIPMENT COMPANY | SCRANTON | PA |
| Industrial Gasket & Shim Co | Meadow Lands | PA |
| Industrial Insulation Inc. | Pittsburgh | PA |
| Industrial Steel Corp. | Carnegie | PA |
| INDUSTRIAL VALLEY BANK – 17TH & MARKET STREETS | PHILADELPHIA | PA |
| INGERSOLL BAND CO | ATHENS | PA |
| INGERSOLL RAND COMPANY | EASTON | PA |
| INGERSOLL RAND COMPANY | PITTSBURGH | PA |
| INGERSOLL SERGEANT DRILL COMPANY | EASTON | PA |
| INGERSOLL SERGEANT DRILL COMPANY | ODENNELDER, EASTON | PA |
| INGERSOLL-RAND COMPANY | ATHENS | PA |
| INGRAM RICHARDSON COMPANY | BEAVER FALLS | PA |
| INLAND CONTAINER CORPORATION | PHILADELPHIA | PA |
| INLAND PRODUCTS | PITTSBURG | PA |
| INLAND PRODUCTS, INCORPORATED | PITSBURGH | PA |
| Inn of America | New Stanton | PA |
| Inolex Chemical | Philadelphia | PA |
| INOLEX CHEMICAL COMPANY | STPHILADELPHIA | PA |
| INSOLITE REFRACTORIES CO | PITTSBURGH | PA |
| Insulation Sales Co | Erie | PA |
| Insulation Sales Company | Neville Island | PA |
| Insulation Sales Company | Pittsburgh | PA |
| Insuldeck Corp | Bath | PA |
| Interlake Iron Co. | Erie | PA |
| Internal Revenue Service Building | Philadelphia | PA |
| International Boiler Works | East Stroudsburg | PA |
| International Boiler Works | E Stroudsburg | PA |
| INTERNATIONAL BOILER WORKS | EAST STROUDABURG | PA |
| INTERNATIONAL BOILER WORKS CO | STROUDSBURG | PA |
| INTERNATIONAL BUSINESS MACHINES (IBM) BUILDING – BATHGATE ROAD | BETHLEHEM | PA |
| INTERNATIONAL BUSINESS MACHINES (IBM) BUILDING – MARKET STREET | PHILADELPHIA | PA |
| INTERNATIONAL MOTOR COMPANY | ALLENTOWN | PA |
| INTERNATIONAL MOTOR COMPANY | EAST PENN JUNCTION | PA |
| International Paper | Alden | PA |
| INTERNATIONAL PAPER CO. | LOCK HAVEN | PA |
| International Paper Company | Erie | PA |
| INTERNATIONAL PAPER COMPANY | YORK HAVEN | PA |
| INTERNATIONAL PAPER COMPANY | ALDAN BOROUGH | PA |
| INTERNATIONAL PAPER COMPANY | TOWANDA | PA |
| INTERNATIONAL PAPER COMPANY, CONTAINER DIVISION | WALTZ MILLS | PA |
| International Pipe and Ceramics Corp. | Emmaus | PA |
| INTERNATIONAL SALT COMPANY – HEADQUARTERS BUILDING – ROUTE 307 AND COUNTRY CLUB ROAD | CLARKS SUMMIT | PA |
| INTERNATIONAL SERVICE IND. | SCRANTON | PA |
| International Shoe Company – Frankford Tannery | Philadelphia | PA |
| INTERSTATE RAILWAYS COMPANY | PHILADELPHIA | PA |
| Ionics Corp | Bridgeville | PA |
| IONICS MANUFACTURING PLANT | BRIDGEVILLE | PA |
| IOWA BARB WIRE COMPANY | ALLENTOWN | PA |
| IOWA BARBED WIRE COMPANY | ALLENTOWN | PA |
| IRON CITY HEATING COMPANY | PITTSBURGH | PA |
| IRON CITY IMP. COMPANY | PITTSBURGH | PA |
| IRON CITY INDUSTRIAL CLEANING CORP. | PITTSBURGH | PA |
| IROQUOIS APARTMENTS | PITTSBURGH | PA |
| Irvin Works | West Mifflin | PA |
| IRWIN WORKS | IRWIN | PA |
| ISABELLA FURNACE COMPANY | ETNA | PA |
| ISIMBEL BROTHERS STABLE | PHILADELPHIA | PA |
| ISLAND PETROLEUM COMPANY | NEVILLE ISLAND | PA |
| ISLAND PETROLEUM COMPANY, NEVILLE ISLAND | PITTSBURGH | PA |
| ITE CIRCUIT BREAKER COMPANY | PHILADELPHIA | PA |
| ITT Fluid Products | Lancaster | PA |
| IVB BUILDING | PHILADELPHIA | PA |
| Ivor J Lee Co | Sharon | PA |
| IVY ROCK FARM | CONSHOHOCKEN | PA |
| J & L STEEL | ALIQUIPPA | PA |
| J & L STEEL | LABELLE | PA |
| J & L STEEL CORP | HAZELWOOD | PA |
| J & L STEEL CORP – ALIQUIPPA WORKS | ALIQUIPPA | PA |
| J & L STEEL CORP – PITTSBURGH WORKS | PITTSBURGH | PA |
| J B Eurell Company | Lansdowne | PA |
| J B VAN SCIVER | ABINGTON | PA |
| J D GROVER AND SONS | PHILADELPHIA | PA |
| J&L Steel | Aliquippa | PA |
| J&L Steel | Ambridge | PA |
| J&L/LTV Steel | Aliquippa | PA |
| J. AND C. NICHOLSON TRUSTEE | ELWOOD CITY | PA |
| J. AND L. SOUTHSIDE | SOUTHSIDE | PA |
| J. AND R. MEILY | LEBANON | PA |
| J. AND W. YEWDALL | PHILADELPHIA | PA |
| J. B. VEATCH – TRUCK STATION 103 | ALIQUIPPA | PA |
| J. BISHOP AND CO | MALVERN | PA |
| J. E. Baker Company | York | PA |
| J. H. & C. K. Eagle | Shamokin | PA |
| J. LANGDON AND COMPANY INCORPORATED | SHAMOKIN | PA |
| J. MUNDELL AND COMPANY | PHILADELPHIA | PA |
| J. WOOD COMPANY | CONSHOCKEN | PA |
| J.A. DOUGHERTY’S SONS | PHILADELPHIA | PA |
| J.A. KOHLHEPP SONS | DU BOIS | PA |
| J.B. ELLISON AND SONS | PHILADELPHIA | PA |
| J.B. LIPPINCOTT BUILDING | PHILADELPHIA | PA |
| J.B. SWAYNE & SON | KENNETT SQUARE | PA |
| J.C. GRAHAM | PHILADELPHIA | PA |
| J.C. GRAHAM AND COMPANY | PHILADELPHIA | PA |
| J.C. GREENWOOD ASSOCIATION, INCORPORATED | BELLE VERNON | PA |
| J.C. GROVER & SONS | PHILADELPHIA | PA |
| J.C. KLAUDER | PHILADELPHIA | PA |
| J.C. KLAUDER ESTATE, 19 NORTH 6TH ST. | PHILADELPHIA | PA |
| J.C. MCDOWELL | PITTSBURGH | PA |
| J.D. FERRY COMPANY | HARRISBURG | PA |
| J.D. GROVER & SONS | PHILADELPHIA | PA |
| J.D. MORRISSEY, INCORPORATED | PHILADELPHIA | PA |
| J.E. Baker Company | Billmayer | PA |
| J.E. BAKER COMPANY | YORK | PA |
| J.E. PATTERSON | WILKES BARRE | PA |
| J.E. PATTERSON AND COMPANY | PITTSTON | PA |
| J.E. POTTER AND COMPANY | PHILADELPHIA | PA |
| J.F. BETZ AND SONS | PHILADELPHIA | PA |
| J.F. BUCHANAN AND COMPANY | PHILADELPHIA | PA |
| J.F: BETZ AND SON | PHILADELPHIA | PA |
| J.G. BRILL AND COMPANY | PHILADELPHIA | PA |
| J.G. BRILL COMPANY | GRAYS FERRY | PA |
| J.G. BRILL COMPANY | PHILADELPHIA | PA |
| J.G. WHITE AND COMPANY | PALO ALTO | PA |
| J.H. AND C.K. EAGLE | SHAMOKIN | PA |
| J.H. AND C.K. EAGLE COMPANY | SHAMOKIN | PA |
| J.H. MICHENER AND COMPANY | PHILADELPHIA | PA |
| J.H. STERNBERGH. AND SON | READING | PA |
| J.H. WILCOX | CHESTER | PA |
| J.J. DE KINDER | PHILADELPHIA | PA |
| J.J. FELIN COMPANY, INCORPORATED | NICETOWN | PA |
| J.J. VANDERGRIFT | PITTSBURGH | PA |
| J.J. White Company | Marcus Hook | PA |
| J.K. MOSSER COMPANY | NOXEN | PA |
| J.K. WRIGHT AND COMPANY | PHILADELPHIA | PA |
| J.P. AUSTIN ASSOCIATES INC/A-TOPS VERMICULITE – EXFOLIATION FACILITY | BEAVER FALLS | PA |
| J.P. MALONEY | SCRANTON | PA |
| J.S. AND T. ELKINTON | PHILADELPHIA | PA |
| J.S. WENTZ | MAUCH CHUNK | PA |
| J.T. BENNETT COMPANY | PHILADELPHIA | PA |
| J.W. ARROTT | PITTSBURGH | PA |
| J.W. IVORY COMPANY | PHILADELPHIA | PA |
| J.W. KOCH COMPANY | HARRISBURG | PA |
| J.W. REX COMPANY | LANSDALE | PA |
| JACOB H. BOWERS | TRAPPE | PA |
| JACOBY HEATING INC | HARRISBURG | PA |
| JACOBY HEATING, INCORPORATED | HARRISBURG | PA |
| JAMES C. MORRISSEY | PHILADELPHIA | PA |
| JAMES IRWIN AND COMPANY | PITTSBURGH | PA |
| JAMES L. STUART | PITTSBURGH | PA |
| JAMES LEES AND SONS COMPANY | BRIDGEPORT | PA |
| JAMES MARTIN AND COMPANY | PHILADELPHIA | PA |
| JAMES MCKAY COMPANY | MCKEES ROCKS | PA |
| JAMES P. WOOD HEATING COMPANY | PHILADELPHIA | PA |
| JAMES REED POWER STREET | PITTSBURGH | PA |
| James S. Wilson Junior High School | Erie | PA |
| JAMES WOLFENDEN | LOCK HAVEN | PA |
| JAMESON COAL AND COKE COMPANY | GREENSBURG | PA |
| JAMESON COAL AND COKE COMPANY | CRAB TREE | PA |
| JAMISON COAL AND COKE COMPANY | GREENSBURG | PA |
| JAMISON COAL AND COKE COMPANY | PITTSBURGH | PA |
| JAMISON COAL AND COKE COMPANY | FORBES ROAD | PA |
| JAMISON COAL AND COKE COMPANY | HANNASTOWN | PA |
| JAMISON COAL AND COKE COMPANY | CRAB TREE | PA |
| JAMISON COAL AND COKE COMPANY | LUXOR | PA |
| Janney Cylinder | Philadelphia | PA |
| JANNISON COAL AND COKE COMPANY | FORBES ROAD | PA |
| JAS. BONAR AND COMPANY | PITTSBURGH | PA |
| JAUNTY FABRIC CORPORATION | SCRANTON | PA |
| JAUNTY SILK COMPANY INCORPORATED | SCRANTON | PA |
| JAWOOD LUKENS | CONSHOHOCKEN | PA |
| JAWOOD LUKENS | EAST CONSHOHOCKEN | PA |
| JEANNETTE GLASS COMPANY | JEANNETTE | PA |
| Jeannette Shade & Novelty Company | Jeannette | PA |
| JEDDO HIGHLAND COAL COMPANY | JEDDO | PA |
| JEFFERSON & CLEARFIELD COAL & IRON COMPANY | PUNXSUTAWNEY | PA |
| JEFFERSON & CLEARFIELD COAL & IRON COMPANY | ERNEST | PA |
| JEFFERSON COAL COMPANY | COAL GLEN | PA |
| JEFFERSON HOSPITAL | PHILADELPHIA | PA |
| JENNY CYLINDER | PHILADELPHIA | PA |
| JERE WOODRING AND COMPANY | HAZELTON | PA |
| JERE WOODRING AND COMPANY | HAZLETON | PA |
| JERMYN AND COMPANY | PITTSTON | PA |
| JERMYN BOILER HOUSE | JERMYN | PA |
| JERSEY CEREAL FOOD COMPANY | IRWIN | PA |
| JERSEY SHORE STEEL COMPANY | AVIS | PA |
| JESSE W. STARR JR. | PHILADELPHIA | PA |
| Jessop Steel | Washington | PA |
| JESSOP STEEL CO | WASHINGTON | PA |
| JESSOP STEEL COMPANY | WASHINGTON | PA |
| JESSOP STEEL CORPORATION | WASHINGTON | PA |
| JESSOP STEEL PLANT | WASHINGTON | PA |
| JESSOPS STEEL COMPANY | WASHINGTON | PA |
| JESSUP AND MOORE, CHESTER MILLS | MODENA | PA |
| JETRONIC INDUSTRIES | PHILADELPHIA | PA |
| JEWISH HOME FOR THE AGED | PHILADELPHIA | PA |
| JEWISH HOSPITAL | PHILADELPHIA | PA |
| Jh France Refractories Company | Snow Shoe | PA |
| JNO. A. RIGG | PHILADELPHIA | PA |
| JNO. F. WILCOX | PITTSBURGH | PA |
| JOEL J. BAILEY AND COMPANY | PHILADELPHIA | PA |
| JOHN A. RIGG | READING | PA |
| JOHN A. RIGG | LEBANON | PA |
| JOHN B. STETSON | PHILADELPHIA | PA |
| JOHN B. STETSON COMPANY | PHILADELPHIA | PA |
| JOHN BARTRAM SENIOR HIGH SCHOOL | PHILADELPHIA | PA |
| JOHN BISTELSON COMPANY | PHILADELPHIA | PA |
| JOHN BOOMLEY AND SONS | PHILADELPHIA | PA |
| JOHN BROMLEY AND SONS | PHILADELPHIA | PA |
| JOHN BROWN’S SONS | PHILADELPHIA | PA |
| JOHN COHEN CLOTHES | PHILADELPHIA | PA |
| John David Company | Philadelphia | PA |
| JOHN DIMLING | PITTSBURGH | PA |
| JOHN F. CASEY, INCORPORATED, PULLMAN STANDARD | BUTLER | PA |
| JOHN H. WEBSTER ELEMENTARY SCHOOL | PHILADELPHIA | PA |
| John Harrison Company | Pittsburgh | PA |
| JOHN LANG | PHILADELPHIA | PA |
| JOHN LANG PAPER COMPANY | PHILADELPHIA | PA |
| JOHN M GRASSE ELEM SCHOOL | HILLTOWN | PA |
| JOHN MOFFET ELEMENTARY SCHOOL – COLUMBIA & MASHER STREETS | PHILADELPHIA | PA |
| JOHN MUNDELL AND COMPANY | PHILADELPHIA | PA |
| JOHN POTERO COMPANY | PHILADELPHIA | PA |
| JOHN S. PEPSON | UNIONTOWN | PA |
| JOHN TACK & SONS | BUTLER | PA |
| John Tearney Heating & Plumbing | Lancaster | PA |
| JOHN TYSON | MOODVILLE | PA |
| JOHN VEITH COLLIERY | MINERSVILLE | PA |
| JOHN WANAMAKER DEPARTMENT STORE | PHILADELPHIA | PA |
| John Wanamaker Store | King of Prussia | PA |
| John Wanamakers | Philadelphia | PA |
| John Wanamakers Dept. Store | Philadelphia | PA |
| JOHN WOOD COMPANY | CONSHOHOCKEN | PA |
| JOHN WOOD MANUFACTURING COMPANY | CONSHOHOCKEN | PA |
| JOHN YEWDALL KEYSTONE MILLS | PHILADELPHIA | PA |
| JOHN ZIMMERMANN AND SONS | PHILADELPHIA | PA |
| JOHNNYS GAS STATION | AMBRIDGE | PA |
| Johns Manville | Pittsburgh | PA |
| JOHNS MANVILLE PRODUCTS COMPANY | ZELEINOPLE | PA |
| JOHNSON AND COMPANY | JOHNSTOWN | PA |
| JOHNSON COMPANY | JOHNSTOWN | PA |
| JOHNSTON THE FLORIST | IRWIN | PA |
| Johnstown Water Authority | Johnstown | PA |
| JOHNSTOWN WATER COMPANY – WATER PLANT | JOHNSTOWN | PA |
| JONATHAN RING AND SON | PHILADELPHIA | PA |
| JONES & LABORLIN STEEL | PITTSBURGH | PA |
| JONES & LAUGHLIN (J&L) STEEL | PITTSBURGH | PA |
| Jones & Laughlin Steel | Hazelwood | PA |
| Jones & Laughlin Steel | Hazelwood-Pittsburgh | PA |
| Jones & Laughlin Steel | Braddock | PA |
| Jones & Laughlin Steel | Philadelphia | PA |
| JONES & LAUGHLIN STEEL | PITTSBURGH | PA |
| JONES & LAUGHLIN STEEL | ALIQUIPPA | PA |
| Jones & Laughlin Steel Co | Aliquippa | PA |
| Jones & Laughlin Steel Co | Pittsburgh | PA |
| Jones & Laughlin Steel Co. | Pittsburgh | PA |
| JONES & LAUGHLIN STEEL COMPANY | ALIQUIPPA | PA |
| JONES & LAUGHLIN STEEL COMPANY | PITTSBURGH | PA |
| JONES & LAUGHLIN STEEL COMPANY – ELIZA FURNACE PLANT | VINTONDALE | PA |
| Jones & Laughlin Steel Company (N/K/A LTV Steel) | Pittsburgh | PA |
| Jones & Laughlin Steel Company (N/K/A LTV Steel) | Aliquippa | PA |
| JONES & LAUGHLIN STEEL CORP | Vestaburg | PA |
| JONES & LAUGHLIN STEEL CORP – SOUTH SIDE | PITTSBURGH | PA |
| JONES & LAUGHLIN STEEL CORP. | PITTSBURGH | PA |
| Jones & Laughlin Steel Corp. (Coke Oven Plant) | Aliquippa | PA |
| Jones & Laughlin Steel Corp. (Eliza Furnaces) | Pittsburgh | PA |
| Jones & Laughlin Steel Corporation | Aliquippa | PA |
| Jones & Laughlin Steel Corporation | Hazelwood | PA |
| Jones & Laughlin Steel Corporation, Southside Works | Pittsburgh | PA |
| JONES & LAUGHLIN STEEL, PITTSBURGH WORKS, FOUNDRY BRICK SHED | PITTSURGH | PA |
| JONES AND LAUGHLIN | PITTSBURGH | PA |
| Jones and Laughlin Steel | Alquippa | PA |
| JONES AND LAUGHLIN STEEL | ALIQUIPPA | PA |
| JONES AND LAUGHLIN STEEL – ALIQUIPPA WORKS | ALIQUIPPA | PA |
| Jones and Laughlin Steel Co. – 2942 Second Avenue – Station No. 63 | Pittsburgh | PA |
| Jones and Laughlin Steel Co. – South Side Works – Station #52-2332 | Pittsburgh | PA |
| JONES AND LAUGHLIN STEEL COMPANY | PITTSBURGH | PA |
| JONES AND LAUGHLIN STEEL COMPANY | WOODLAWN | PA |
| JONES AND LAUGHLIN STEEL COMPANY | WOODLAND | PA |
| JONES AND LAUGHLIN STEEL COMPANY – SOUTH SIDE WORKS | PITTSBURGH | PA |
| Jones And Laughlin Steel Corp. | Aliquippa | PA |
| JONES AND LAUGHLIN STEEL CORPORATION | PITTSBURGH | PA |
| JONES AND LAUGHLIN STEEL CORPORATION | WOODLAWN | PA |
| JONES AND LAUGHLIN STEEL CORPORATION | ELIZA | PA |
| JONES AND LAUGHLIN STEEL CORPORATION | ALIQUIPPA | PA |
| JONES AND LAUGHLIN STEEL CORPORATION SOLO WORKS | PITTSBURGH | PA |
| JONES AND LAUGHLIN, LIMITED | PITTSBURGH | PA |
| JONES JUNIOR HIGH SCHOOL- ANN & MEMPHIS STREETS | PHILADELPHIA | PA |
| JORDAN PARK APARTMENTS – BOILER HOUSE | FULLERTON | PA |
| JOSEPH AND THROPP | EARLSTON | PA |
| JOSEPH BERLINER COMPANY | PHILADELPHIA | PA |
| JOSEPH CAMPBELL PET FOODS | LIME RIDGE | PA |
| JOSEPH HEACOCK | WYNCOTE | PA |
| JOSEPH HORNE AND COMPANY | PITTSBURGH | PA |
| JOSEPH R. FOSTER SONS | PHILADELPHIA | PA |
| JOSEPH S. FINCH & CO. | SCHENLY | PA |
| JOSEPH S. FINCH AND COMPANY | SCHENLEY | PA |
| JOSEPH S. FINCH AND COMPANY | SCHENELY | PA |
| JOSEPH S. FINCH COMPANY | PITTSBURGH | PA |
| JOSEPHINE FURNACE AND COKE COMPANY | JOSEPHINE | PA |
| JOY MANUFACTURING | NEW PHILADELPHIA | PA |
| JOY MANUFACTURING | FRANKLIN | PA |
| JOY MANUFACTURING | RENO | PA |
| Jp Austin Associated Inc | Pittsburgh | PA |
| Jp Austin Associated Inc | Homestead | PA |
| JSTA. #30 – S. S. BOILER HSE. | PITTSBURGH | PA |
| JULIUS KAYSER COMPANY – CROWN SILK MILL | BANGOR | PA |
| JUNIATA COMPANY | MUFFLINTOWN | PA |
| JUNIATA FURNACE AND FOUNDRY COMPANY | NEWPORT | PA |
| JUNIOR HIGH SCHOOL | ALIQUIPPA | PA |
| JUSTI DIVISION W. GOLD REF. | PHILADELPHIA | PA |
| K & L REFRACTORIES | ERIE | PA |
| K & L Refractory Service | Erie | PA |
| Kaiser Engineers | Bristol | PA |
| KAISER JOB | BUTLER | PA |
| KAISER METAL | BRISTOL | PA |
| KAMAK MILLS | KULPMONT | PA |
| Kane Area Junior High School | Kane | PA |
| KANE SCHOOL – 26TH & JEFFERSON | PHILADELPHIA | PA |
| KANMAK MILLS | KULPMONT | PA |
| KARL LIEBERKNECHT INC. (a/k/a Rosedale Knitting Mills) | READING | PA |
| KARL R.H. KNAPP, INCORPORATED, 1015 PERALTA ST. | PITTSBURGH | PA |
| KARL R.H. KNAPP, INCORPORATED, THOMAS ST. AND MCKEES AVE. | MCKEES ROCK | PA |
| Katz Underwear Co. | Honesdale | PA |
| Kaufman Building | Pittsburgh | PA |
| KAUFMANN’S DEPARTMENT STORE | PITTSBURGH | PA |
| KAUFMANS DEPARTMENT STORE | PITTSBURGH | PA |
| KAWECKI BERYLCO | HAZELTON | PA |
| KAWECKI BERYLCO IND. | READING | PA |
| KAWECKI BERYLCO IND. | TEMPLE | PA |
| KAWECKI BERYLCO INDUSTRIES, INCORPORATED | BOYERTOWN | PA |
| KAWECKI BERYLCO PLANT | HAZLETON | PA |
| KAWECKI CHEMICAL COMPANY | BOYERTON | PA |
| KAWECKI CHEMICAL COMPANY | READING | PA |
| KAWECKI CHEMICAL COMPANY | BOVERTOWN | PA |
| KAWECKI CHEMICAL COMPANY | HOOVERTOWN | PA |
| KAWECKI CHEMICAL COMPANY | BOYERTOWN | PA |
| KAWECKI CHEMICAL COMPANY | RUPERTOWN | PA |
| KAWEENER CO. | BLOOMSBURG | PA |
| KAWEENER CO. | HARRISBURG | PA |
| KAWNEER CO INC | BLOOMSBURG | PA |
| Keasbey & Mattison | Ambler | PA |
| Keasbey & Mattison Plant | Ambler | PA |
| KEASBEY AND MATTISON | PHILADELPHIA | PA |
| KEASBEY AND MATTISON COMPANY | AMBLER | PA |
| KEASBY & MATTISON | AMBLER | PA |
| KEEBLER BISCUITS COMPANY | PHILADELPHIA | PA |
| KEENAN CO | PHILADELPHIA | PA |
| KEENAN COMPANY | PHILADELPHIA | PA |
| Keene Corporation | Valley Forge | PA |
| KEITH’S THEATRE | PHILADELPHIA | PA |
| KELLER CREAMERY | HARLEYSVILLE | PA |
| Kelloggs | Lancaster | PA |
| KELLY AND JONES COMPANY | GREENSBURG | PA |
| KELLY AND JONES COMPANY | PITTSBURGH | PA |
| KELLY AND LUDWIG | PHILADELPHIA | PA |
| KELLY WOODEN WARE COMPANY | WATERFORD | PA |
| KELSEY HAYES WHEEL COMPANY | MCKEESPORT | PA |
| KEMBLE IRON COMPANY | RIDDLESBURG | PA |
| KEMMERER IRON AND STEEL COMPANY | SCRANTON | PA |
| Kendall Oil Co | Bradford | PA |
| Kendall Oil Co. – Laboratory | Bradford | PA |
| KENDALL REFINING CO. | BRADFORD | PA |
| Kendall Refining Company | Bradford | PA |
| KENDALL REFINING COMPANY (a/k/a Kendall Refining) | BRADFORD | PA |
| KENNAMETAL, INCORPORATED | LATROBE | PA |
| KENNEDY VAN SAUN | DANVILLE | PA |
| KENNEDY VAN SAUN C/O WARNER | DEVAULT | PA |
| Kensington Water Co. | New Kensington | PA |
| KEPLERS FUEL COMPANY | EASTON | PA |
| KEPPARS CO | PETROLIA | PA |
| KEYSTONE | ELDERTON | PENNSYLVANIA |
| KEYSTONE ASBESTOS MAGNESIA COMPANY | ETNA | PA |
| KEYSTONE BREWERS, INCORPORATED | PITTSBURGH | PA |
| Keystone Cement | Bath | PA |
| KEYSTONE CHEMURGIC PLANT | BETHLEHEM | PA |
| KEYSTONE COAL AND COKE COMPANY | GREENSBURG | PA |
| KEYSTONE COAL AND COKE COMPANY | NEW ALEXANDRIA | PA |
| KEYSTONE COAL AND COKE COMPANY | ELLSWORTH | PA |
| KEYSTONE COAL AND COKE COMPANY | MADISON | PA |
| KEYSTONE COAL AND COKE COMPANY | MADISON MINES | PA |
| KEYSTONE COAL AND COKE COMPANY | DUNDALE | PA |
| KEYSTONE DRAWN STEEL | SPRING CITY | PA |
| Keystone Drydock | Philadelphia | PA |
| KEYSTONE ENGINEERING COMPANY | PITTSBURGH | PA |
| Keystone Generating Station | Elderton | PA |
| Keystone Generating Station – Unit 1 | Elderton | PA |
| Keystone Generating Station – Unit 2 | Elderton | PA |
| Keystone Pipe and Supply | Butler | PA |
| KEYSTONE PLANTATION | WYOMING | PA |
| KEYSTONE PORTLAND | BATH | PA |
| KEYSTONE PORTLAND CEMENT | BATH | PA |
| KEYSTONE PORTLAND CEMENT | PHILADELPHIA | PA |
| Keystone Portland Cement Company | Bath | PA |
| KEYSTONE POWER PLANT | INDIANA | PA |
| Keystone Power Station | Shelocta | PA |
| KEYSTONE PROJECT – CLAIRTON WORKS | CLAIRTON | PA |
| KEYSTONE PROJECT, CLAIRTON WORKS | CLAIRTON | PA |
| KEYSTONE PROJECT, WESTINGHOUSE ELECTRIC | ELDERTON | PA |
| KEYSTONE RESOURCES | MARS | PA |
| KEYSTONE ROOFING COMPANY | YORK | PA |
| KEYSTONE SHAFT MINE | MADISON | PA |
| KEYSTONE STATION – UNITS 1 AND 2 – WESTINGHOUSE TURBINES AND GENERATORS | SHELOCTA | PA |
| Keystone Wire & Iron | Huntingdon Valley | PA |
| KEYSTONE WOOLEN MILLS | CONSHOHOCKEN | PA |
| KIBBE, CHAFFIE AND COMPANY | PHILADELPHIA | PA |
| KIBBE’S SPECIALTY CONTRACTORS | S. WILLIAMSPORT | PA |
| KIMBERLY CLARK CORPORATION | MT HOLLY SPRINGS | PA |
| King Keystone | Warren | PA |
| KING OF PRUSSIA SHOPPING CENTER | KING OF PRUSSIA | PA |
| KINGAN AND COMPANY, LIMITED | PHILADELPHIA | PA |
| KINGSTON COAL COMPANY | KINGSTON | PA |
| KINGSTON COAL COMPANY, NUMBER 2 SHAFT | KINGSTON | PA |
| KINGSTON COAL COMPANY, NUMBER 4 BREAKER COLLY | KINGSTON | PA |
| Kingston Colleries | PA | |
| KINSEY DISTILLING CO | LINFIELD | PA |
| KITTANNING BRICK AND FIRE CLAY COMPANY | PITTSBURGH | PA |
| KITTANNING CERAMICS COMPANY | KITTANNING | PA |
| KITTANNING PLATE GLASS COMPANY | KITTANNING | PA |
| Klien Chocolate Company | Elizabethtown | PA |
| KLUR FRANK CO | PITTSBURGH | PA |
| Knitting Factory | Dallas | PA |
| KNOBLIT – RICHMOND STREET | PHILADELPHIA | PA |
| KNOLL PRODUCTS, INC. | HANOVER TOWNSHIP | PA |
| KNOUSE CORPORATION | PEACH GLEN, ADAMS COUNTY | PA |
| KNOUSE FOODS COOPERATIVE, INCORPORATED | ORRTANNA | PA |
| KOLNILE BREWING COMPANY | PHILADELPHIA | PA |
| KOPP GLASS | SWISSVALE | PA |
| Koppel Plant | Beaver Falls | PA |
| Koppel Steel Company | Ambridge | PA |
| Koppel Steel Company | Beaver Falls | PA |
| Koppers | Monaca | PA |
| Koppers | Philadelphia | PA |
| Koppers | Pittsburgh | PA |
| KOPPERS | FAIRLESS HILLS | PA |
| Koppers Building – Office | Pittsburgh | PA |
| Koppers Co. | Pittsburgh | PA |
| KOPPERS CO. | MCKEES ROCKS | PA |
| KOPPERS CO., INC. | KOBUTA | PA |
| KOPPERS COMPANY | PETROLIA | PA |
| KOPPERS COMPANY | JOSEPHTOWN | PA |
| Koppers Company (a/k/a Arco/Polymers, Inc. or Sinclair-Koppers) | Kabuta | PA |
| KOPPERS COMPANY INC | MONROEVILLE | PA |
| KOPPERS COMPANY INC | VERONA | PA |
| KOPPERS COMPANY INC | PETROLIA | PA |
| Koppers Company Inc. | Oil City | PA |
| KOPPERS COMPANY INC. – CHEMICAL DIVISION | BEAVER | PA |
| Koppers Company, Inc. | Kobuta | PA |
| Koppers Company, Inc. | Petrolia | PA |
| Koppers Company, Inc. | Pittsburgh | PA |
| KOPPERS COMPANY, INC. | MONACA | PA |
| KOPPERS COMPANY, INC. | VERONA | PA |
| Koppers Company, Inc. | Bridgeville | PA |
| KOPPERS COMPANY, INC. – CHEMICAL DIVISION | BEAVER | PA |
| KOPPERS COMPANY, INC. – CHEMICAL DIVISION | EDWIN | PA |
| KOPPERS COMPANY, INC. – CHEMICAL DIVISION – KOBUTA | BEAVER | PA |
| KOPPERS COMPANY, INC. – CHEMICAL DIVISION – OIL CITY PLANT | OIL CITY | PA |
| KOPPERS COMPANY, INC. – CHEMICAL DIVISION – PENACOL PLANT | PETROLIA | PA |
| KOPPERS COMPANY, INC. – CHEMICALS & DYESTUFFS DIV | PETROLIA | PA |
| KOPPERS COMPANY, INC. – COAL HYDROGENATION PILOT PLANT | VERONA | PA |
| KOPPERS COMPANY, INC. – DYLITE PLANT | KOBUTA | PA |
| KOPPERS COMPANY, INC. – ELASTIC DIVISION | KOBUTA | PA |
| KOPPERS COMPANY, INC. – GENERAL COMMODITIES WAREHOUSE | PITTSBURGH | PA |
| KOPPERS COMPANY, INC. – KOBUTA | BEAVER | PA |
| KOPPERS COMPANY, INC. – KOBUTA | KOBUTA | PA |
| KOPPERS COMPANY, INC. – ORGANIC MATERIALS DIV | OIL CITY | PA |
| KOPPERS COMPANY, INC. – PENACOL PLANT | PETROLIA | PA |
| KOPPERS COMPANY, INC. – PENACOL PLANT – CHEMICAL DIV. | PETROLIA | PA |
| KOPPERS COMPANY, INC. – PENACOL PLANT – CHEMICAL DIVISION | PETROLIA | PA |
| KOPPERS COMPANY, INC. – PENTACOL PLANT | PETROLIA | PA |
| KOPPERS COMPANY, INC. – PETOLIA PLANT | PETROLIA | PA |
| KOPPERS COMPANY, INC. – PIPING POLYSTRENE PLANT | KOBUTA | PA |
| KOPPERS COMPANY, INC. – PLASTICS DIVISION | KOBUTA | PA |
| KOPPERS COMPANY, INC. – PLASTICS DIVISION | MONACA | PA |
| KOPPERS COMPANY, INC. – PLASTICS DIVISION – KOBUTA PLANT | KOBUTA | PA |
| KOPPERS COMPANY, INC. – TAR & CHEM DIV | OIL CITY | PA |
| KOPPERS COMPANY, INC. – TAR PRODUCTS DIVISION | NEW NORRISTOWN | PA |
| KOPPERS COMPANY, INC. – TAR PRODUCTS DIVISION | OIL CITY | PA |
| KOPPERS COMPANY, INC. – TAR PRODUCTS DIVISION | SWEDELAND | PA |
| KOPPERS COMPANY, INC. – VERONA RESEARCH | VERONA | PA |
| KOPPERS COMPANY, INC. – VERONA RESEARCH CENTER | VERONA | PA |
| Koppers Company, Inc. (Air Reduction) | Johnstown | PA |
| KOPPERS COMPANY, INC. CHEMICAL DIVISION – OIL CITY PLANT | OIL CITY | PA |
| KOPPERS COMPANY, INC. CHEMICAL DIVISION – PENACOL PLANT | PETROLIA | PA |
| KOPPERS COMPANY, INCORPORATED | PITTSBURGH | PA |
| KOPPERS COMPANY, INCORPORATED, KOPPERS BUILDING | PITTSBURGH | PA |
| KOPPERS PITTSBURGH CO | BRIDGEVILLE | PA |
| KOPPERS PITTSBURGH CO – BLDG 35 | BRIDGEVILLE | PA |
| KOPPERS PLANT | BRIDGEVILLE | PA |
| KOPPERS PLANT | PETROLIA | PA |
| KOPPERS PLANT | VERONA | PA |
| KOPPERS RESEARCH LAB | MONROEVILLE | PA |
| Korhumel Steel & Aluminum Company-Mill Strip Division | New Castle | PA |
| KORVETTES SHOPPING CENTER | PHILADELPHIA | PA |
| KRAFT FOODS | FOGELSVILLE | PA |
| KRAFT FOODS COMPANY | PALMYRA | PA |
| Kutz Engineering | Pittsburgh | PA |
| KUTZTOWN FOUNDRY | KUTZTOWN | PA |
| KUTZTOWN FOUNDRY AND MACHINE | KUTZTOWN | PA |
| KUTZTOWN HIGH SCHOOL | KUTZTOWN | PA |
| L & L HEATING & EQUIPMENT | PHILADELPHIA | PA |
| L & L MANUFACTURING CO. | UPLAND | PA |
| L & N RAILROAD | CONWAY | PA |
| L AND L HEATING AND EQUIPMENT | PHILADELPHIA | PA |
| L C ANDERSON | HUNTINGDON | PA |
| L O BOUQUIN CO | OIL CITY | PA |
| L SONNEBORN SONS INC – DAUGHERTY REFINERY DIVISION | PETROLIA | PA |
| L. GOLDSTEIN’S & SONS, INCORPORATED | PHILADELPHIA | PA |
| L. M. BARE PAPER CO. | ROARING SPRING | PA |
| L. SONNEBORN SONS, INCORPORATED | PETROLIA | PA |
| L. WINTERER | PHILADELPHIA | PA |
| L. WINTERES | PHILADELPHIA | PA |
| L.A. RILEY AND COMPANY | PHILADELPHIA | PA |
| L.A. RILEY AND COMPANY | ASHLAND | PA |
| L.A. RILEY AND COMPANY | CENTRALIA | PA |
| L.H. PARKE COMPANY | PHILADELPHIA | PA |
| L.H. PRENTICE COMPANY | PITTSBURGH | PA |
| L.J. LAND, INCORPORATED | READING | PA |
| L.LAVESON AND SON | PHILADELPHIA | PA |
| LA BELLE WORKS | ALLEGHENY | PA |
| LA BRUM SCHOOL – RED LION & CALERO ROADS | PHILADELPHIA | PA |
| LABOR PRODUCTS AND ICE COMPANY | BRACKENRIDGE | PA |
| LACKAWANNA AND WYOMING VALLEY COMPANY | SCRANTON | PA |
| LACKAWANNA AND WYOMING VALLEY RAILWAY COMPANY | SCRANTON | PA |
| LACKAWANNA COAL AND COKE COMPANY | VINTONDALE | PA |
| LACKAWANNA COAL AND COKE COMPANY | WEHRUM | PA |
| LACKAWANNA COUNTY HIGH RISE FOR THE ELDERLY – JACKSON STREET | SCRANTON | PA |
| Lackawanna Iron & Steel | Lebannon | PA |
| LACKAWANNA IRON AND COAL COMPANY | SCRANTON | PA |
| LACKAWANNA IRON AND STEEL COMPANY | LEBANON | PA |
| LACKAWANNA IRON AND STEEL COMPANY | VINTONDALE | PA |
| LACKAWANNA IRON AND STEEL COMPANY | DONAGHMORE | PA |
| LACKAWANNA IRON AND STEEL COMPANY | DUNAGHMORE | PA |
| LACKAWANNA IRON AND STEEL COMPANY | NORTH CORNWALL | PA |
| LACKAWANNA IRON AND STEEL COMPANY | LABANON | PA |
| LACKAWANNA IRON AND STEEL COMPANY | SCRANTON | PA |
| LACKAWANNA LIGHT COMPANY – POWER PLANT | SCRANTON | PA |
| LACKAWANNA VALLEY ELECTRIC LIGHT AND POWER COMPANY – POWER PLANT | CARBONDALE | PA |
| LACO APPLICATORS, INC. – WAREN STATE BOILER HOUSE | WARREN | PA |
| Laco Mc Mullen Co | Erie | PA |
| LACO MCMULLEN CO | ERIE | PA |
| Laco Sales Inc | Erie | PA |
| LACO-MCMULLEN COMPANY INC. | ERIE | PA |
| LADDIE BOY DIV OF N C C P | PHILADELPHIA | PA |
| LADDIE BOY DOG FOOD COMPANY | PHILADELPHIA | PA |
| LADDIE BOY DOG FOOD CORPA | PHILADELPHIA | PA |
| LAFAYETTE HOTEL | PHILADELPHIA | PA |
| L-AIR LIQUIDE – WALNUT STREET GATE | JOHNSTOWN | PA |
| LAKE | CHESTER | PA |
| LAKELAND HOSPITAL | LAKELAND | PA |
| LAKENS IRON AND STEEL COMPANY | COATESVILLE | PA |
| LANCASTER CLOSURE PLANT | LANCASTER | PA |
| LANCASTER CORK WORKS | LANCASTER | PA |
| LANCASTER COUNTY RAILWAY AND LIGHT COMPANY – POWER PLANT | LANCASTER | PA |
| LANCASTER FLOOR PLANT | LANCASTER | PA |
| LANCASTER FLOOR PLANT BLDG. #500 | LANCASTER | PA |
| LANCASTER FLOOR PLT BLDG 44 | LANCASTER | PA |
| LANCASTER MALLEABLE CASTI | LANCASTER | PA |
| LANCASTER MALLEABLE CASTING COMPANY | LANCASTER | PA |
| LANCASTER MALLEABLE CASTINGS CO | LANCASTER | PA |
| LANCASTER OSTEOPATHIC HOSPITAL | LANCASTER | PA |
| LANCE COLLIERY #11 | PLYMOUTH | PA |
| LANCE COLLIERY #11 | PLYMOUTH JUNCTION | PA |
| LAND TITLE AND TRUST COMPANY | PHILADELPHIA | PA |
| LANDIS MACHINE COMPANY | WAYNESBORO | PA |
| LANDIS TOOL CO | WAYNESBORO | PA |
| LANEHART COMPANY | GREENCASTLE | PA |
| LANKENAU HOSPITAL | PHILADELPHIA | PA |
| LANKENAU HOSPITAL – NURSES SCHOOL | WYNNWOOD | PA |
| LANSDALE ELECTRIC LIGHT DEPARTMENT – MUNICIPAL ELECTRIC-LIGHT PLANT | LANSDALE | PA |
| LANSDALE TUBE | LANSDALE | PA |
| LANSDOWNE STEEL AND IRON CO | MORTON | PA |
| LANSDOWNE TOWERS, INCORPORATED | ALDEN | PA |
| LARGE DISTILLING COMPANY | WILSON | PA |
| LARSON SUPPLY | READING | PA |
| LASKO METAL PRODUCTS, INCORPORATED | WESTCHESTER | PA |
| LATROBE AREA HOSPITAL | LATROBE | PA |
| LATROBE BREWING CO. | LATROBE | PA |
| LATROBE ELECTRIC STEEL COMPANY – STEEL PLANT | LATROBE | PA |
| Latrobe Forge & Spring, Inc. | Latrobe | PA |
| LATROBE FORGE AND SPRING | LATROBE | PA |
| LATROBE FOUNDRY AND MACHINE | LATROBE | PA |
| LATROBE HOSPITAL | LATROBE | PA |
| LATROBE HOSPITAL – NEW ADDITION | LATROBE | PA |
| LATROBE STEEL | LATROBE | PA |
| LATROBE STEEL CO | LATROBE | PA |
| Latrobe Steel Company | Latrobe | PA |
| LATROBE STEEL WORKS | LATROBE | PA |
| LATROBE WORKS | LATROBE | PA |
| LAUREL RUN COAL COMPANY | WILKES BARRE | PA |
| LAUREL RUN COAL COMPANY | MINERS MILLS | PA |
| LAURELTON STATE VILLAGE | LAURELTON | PA |
| LAVA CRUCIBLE REFRACTORIES | ZELIENOPLE | PA |
| LAVINO FURNACE COMPANY | LEBANON | PA |
| Lavino Shipping Company | Philadelphia | PA |
| LAWRENCE CEMENT COMPANY | SIEGFRIED, NORTHAMPTON | PA |
| LAWRENCE CEMENT COMPANY OF PENNSYLVANIA | SIEGFRIED, NORTHAMPTON | PA |
| LEADER PUBLISHING COMPANY | PITTSBURGH | PA |
| LEAGUE ISLAND | PHILADELPHIA | PA |
| Leamington School | Pittsburgh | PA |
| LEAMY HOME MOUNT AIRY | PHILADELPHIA | PA |
| LEBANON BLAST FURNACE COMPANY | LEBANON | PA |
| Lebanon City County Building | Lebanon | PA |
| LEBANON CONCENTRATOR PLANT | LEBANON | PA |
| LEBANON FURNACES | LEBANON | PA |
| LEBANON FURNANCE COMPANY | LEBANON | PA |
| Lebanon Plumbing Supply Co | Lebanon | PA |
| LEBANON STEAM COMPANY – POWER PLANT | LEBANON | PA |
| LEBANON VALLEY COLLEGE – VICKROY HALL – GIRLS DORM | ANNVILLE | PA |
| LEBANON VALLEY IRON WORKS | LEBANON | PA |
| LEBANON VALLEY STREET RAILWAY COMPANY | LEBANON | PA |
| LECTROMELT | PITTSBURGH | PA |
| Ledwig Huntel Company | Sharon Hill | PA |
| Lee Hospital | Johnstown | PA |
| Lee Rubber & Tire Company | Conshohocken | PA |
| LEE TIRE RUBBER | CONSHOHOCKEN | PA |
| Leechburg Supply Co | Leechburg | PA |
| Leeds & Northrop | North Wales | PA |
| Leeds & Northrup | Philadelphia | PA |
| LEEDS & NORTHRUP CO (a/k/a Riggs, Distler & Co.) | NORTH WALES | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | PHILADELPHIA | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | WILKES BARRE | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | ASHLEY | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | PLYMOUTH | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | WANAMIE | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | AUDENRIED | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | AUDEURIED | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | SOUTH WILKESBARRE | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | SUGAR NOTCH | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY | NOTINGHAM COLLIERY | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY, COLLIERY #4 | AUDENRIED | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY, EMPIRE COLLIERY #4 | ASHLEY | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY, HOLLENBACK COLLIERY #2 | WILKES BARRE | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY, STANTON COLLIERY #4 | ASHLEY | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY, SUGAR NOTCH COLLIERY #9 | SUGAR NOTCH | PA |
| LEHIGH AND WILKES BARRE COAL COMPANY, WANAMIE COLLIERY #3 | WANAMIE | PA |
| LEHIGH CAR WHEEL AND AXLE COMPANY | CATASAUQUA | PA |
| LEHIGH COAL AND COMPANY | LANSFORD | PA |
| LEHIGH COAL AND COMPANY | HAUTO | PA |
| LEHIGH COAL AND COMPANY | NESQUEHONING | PA |
| LEHIGH COAL AND COMPANY | TAMAQUA | PA |
| LEHIGH COAL AND IRON COMPANY | LANSFORD | PA |
| LEHIGH COAL AND NAVAGATION COMPANY | LANSFORD | PA |
| LEHIGH COAL AND NAVAGATION COMPANY | PHILADELPHIA | PA |
| LEHIGH COAL AND NAVAGATION COMPANY | NESQUEHONING | PA |
| LEHIGH COAL AND NAVAGATION COMPANY | HAUTO | PA |
| LEHIGH COAL AND NAVIGATION COMPANY | HAUTO | PA |
| LEHIGH COAL AND NAVIGATION COMPANY | PHILADELPHIA | PA |
| LEHIGH COAL AND NAVIGATION COMPANY | WILKES BARRE | PA |
| LEHIGH COAL AND NAVIGATION COMPANY | NESQUEHONING | PA |
| LEHIGH COAL AND NAVIGATION COMPANY | LANSFORD | PA |
| LEHIGH COAL AND NAVIGATION COMPANY | NEW PHILADELPHIA | PA |
| LeHigh Coke Co. | South Bethlehem | PA |
| LEHIGH COKE COMPANY | SOUTH BETHLEHEM | PA |
| LEHIGH COUNTY COURT HOUSE | ALLENTOWN | PA |
| LEHIGH COUNTY HOME | WESCOSVILLE | PA |
| Lehigh Dye & Finishing Co. | Allentown | PA |
| Lehigh Engineering | Bethlehem | PA |
| LEHIGH ENGINEERING CO. – WEST PLANT | HANOVER | PA |
| Lehigh Engineering Company | Dunmore | PA |
| LEHIGH INDUSTRIAL POWER COMPANY | STAUTO | PA |
| LEHIGH INDUSTRIAL POWER COMPANY | HAUTO | PA |
| LEHIGH MANUFACTURING COMPANY | PHILADELPHIA | PA |
| Lehigh Material Company | Philadelphia | PA |
| LEHIGH MATERIALS CO (a/k/a Tamaqua Colliery) | TAMAQUA | PA |
| LEHIGH NAVIGATION ELECTRIC COMPANY – GENERATING STATION | HAUTO | PA |
| Lehigh Parkway School | Allentown | PA |
| LEHIGH PIPE SHOP | BETHLEHEM | PA |
| LEHIGH PORTLAND CEMENT | ALLENTOWN | PA |
| LEHIGH PORTLAND CEMENT – FOGELSVILLE PLANT | ALLENTOWN | PA |
| LEHIGH PORTLAND CEMENT COMPANY | NEW CASTLE | PA |
| LEHIGH PORTLAND CEMENT COMPANY | ORMROD | PA |
| LEHIGH PORTLAND CEMENT COMPANY | ALLENTOWN | PA |
| LEHIGH PORTLAND CEMENT COMPANY | FOGELSVILLE | PA |
| LEHIGH PORTLAND CEMENT COMPANY | WEST COPLAY | PA |
| LEHIGH PORTLAND CEMENT COMPANY | SANDTS EDDY | PA |
| LEHIGH PORTLAND CEMENT COMPANY | BATH | PA |
| LEHIGH PORTLAND CEMENT COMPANY | PAYNES STATION | PA |
| LEHIGH PORTLAND CEMENT COMPANY | WEST COPLEY | PA |
| Lehigh Portland Cement Company – Fogelsville Plant | Fogelsville | PA |
| Lehigh Portland Cement Company – Fogelsville Plant – Young Building | Fogelsville | PA |
| LEHIGH SILK DYEING COMPANY | WEIDMANN | PA |
| LEHIGH UNIVERSITY – MAGINNES HALL OF LIBERAL ARTS | BETHLEHEM | PA |
| Lehigh Valley Coal Co. | PA | |
| LEHIGH VALLEY COAL COMPANY | PHILADELPHIA | PA |
| LEHIGH VALLEY COAL COMPANY | PITTSTON | PA |
| LEHIGH VALLEY COAL COMPANY | WILKES BARRE | PA |
| LEHIGH VALLEY COAL COMPANY | ORWIGSBURG | PA |
| LEHIGH VALLEY COAL COMPANY | WYOMING | PA |
| LEHIGH VALLEY COAL COMPANY | CENTRALIA | PA |
| LEHIGH VALLEY COAL COMPANY | HAZLETON | PA |
| LEHIGH VALLEY COAL COMPANY | JEANSVILLE | PA |
| LEHIGH VALLEY COAL COMPANY | MT. CARMEL | PA |
| LEHIGH VALLEY COAL COMPANY | PITTSTON JUNCTION | PA |
| LEHIGH VALLEY COAL COMPANY | HAZELTON | PA |
| LEHIGH VALLEY COAL COMPANY | PARK PLACE | PA |
| LEHIGH VALLEY COAL COMPANY | JEANSVILLE, HAZELTON | PA |
| LEHIGH VALLEY COAL COMPANY, BLACKWOOD COLLIERY | ORWIGSBURG | PA |
| LEHIGH VALLEY COAL COMPANY, EXETER COLLIERY | PITTSTON | PA |
| LEHIGH VALLEY COAL COMPANY, PROSPECT COLLIERY | WILKES BARRE | PA |
| LEHIGH VALLEY COOPERATIVE FARMERS | ALLENTOWN | PA |
| Lehigh Valley Dairy | Allentown | PA |
| LEHIGH VALLEY R. R. – PRINGLE STREET SIDING | KINGSTON | PA |
| LEHIGH VALLEY RAILROAD | COXTON | PA |
| LEHIGH VALLEY RAILROAD COMPANY | BETHLEHEM | PA |
| LEHIGH VALLEY SUPPLY | ALLENTOWN | PA |
| LEHIGH VALLEY TRACTION COMPANY | ALLENTOWN | PA |
| LEHIGH VALLEY TRANSIT COMPANY – POWER PLANT | ALLENTOWN | PA |
| LEHIGH WATER COMPANY – FILTRATION PLANT | EASTON | PA |
| LEHIGH-NORTHAMPTON GAS AND ELECTRIC COMPANY – POWER PLANT | CATASAUQUA | PA |
| LEHIGHTON ELECTRIC LIGHT, HEAT AND POWER COMPANY – POWER STATION | LEHIGHTON | PA |
| LEICESTER CONTINENTAL MILLS COMPANY | GERMANTOWN | PA |
| LEIDY SCHOOL | PHILADELPHIA | PA |
| LEISENRING AND COMPANY | DUNCOTT | PA |
| LEISENRING AND COMPANY | MINERSVILLE | PA |
| LEITH MINES | LEITH STATION | PA |
| Lenape Elementary School | Ford City | PA |
| LENAPE FORGE, INCORPORATED | WEST CHESTER | PA |
| Leninger Knitting Mills | Mohnton | PA |
| LENTZ AND COMPANY | PARK PLACE | PA |
| LENTZ LILLY AND COMPANY | PARK PLACE | PA |
| LEONARD BROTHERS | SERANTON | PA |
| LEOPOLD VILSACK | PITTSBURGH | PA |
| LESTER INDUSTRIAL BLDG | LESTER | PA |
| LESTER INDUSTRIAL PARK | LESTER | PA |
| Leston Company | Philadelphia | PA |
| LETORT ELEM. SCHOOL | MILLERSVILLE | PA |
| LETORT ELEMENTARY SCHOOL | MILLERSVILLE | PA |
| LETTERKENNY DEPOT | LETTERKENNY | PA |
| Levinson Steel | Mckees Rocks | PA |
| LEWIS BLOCK | PITTSBURGH | PA |
| Lewis Foundry and Machine | Groveton | PA |
| LEWIS FOUNDRY AND MACHINE COMPANY | PITTSBURGH | PA |
| LEWIS S. COX AND COMPANY | PHILADELPHIA | PA |
| LEWISTOWN SMELTING & REFINING CO. | LEWISTOWN | PA |
| LEXINGTON MEAD CORP. | PITTSBURGH | PA |
| LIBERTY BELL RACE TRACK | PHILADELPHIA | PA |
| LIBERTY BUILDING & HEATING, JUNIOR HIGH SCHOOL – HARDING AVE. & MAIN ST. | ALIQUIPPA | PA |
| LIBERTY MANUFACTURING COMPANY | PITTSBURGH | PA |
| LIBERTY MARKET COMPANY | PITTSBURGH | PA |
| LIBERTY POWDER COMPANY | MT. BRADDOCK | PA |
| LICKDALE IRON COMPANY | LICKDALE | PA |
| LIGGETT AND MYERS TOBACCO COMPANY | PHILADELPHIA | PA |
| LIGGETT SPRING AND AXLE COMPANY | MONONGAHELA | PA |
| LILLY WASHINGTON SCHOOL | LILLY | PA |
| Limbach Company | Pittsburgh | PA |
| LIMERICK NUCLEAR POWER PLANT | LIMERICK | PA |
| LINCOLN COAL AND COKE COMPANY | WATERBURG | PA |
| LINCOLN COAL AND COKE COMPANY | SCOTTDALE | PA |
| LINCOLN COAL AND COKE COMPANY | HELEN | PA |
| Lincoln High School | Ellwood City | PA |
| LINCOLN LIBERTY BUILDING | PHILADELPHIA | PA |
| LINCOLN UNIVERSITY – STEAM TUNNELS | OXFORD | PA |
| LINDBERG | NEWTOWN SQUARE | PA |
| LINDE AIR PRODUCTS | KITTANNING | PA |
| Linde Air Products Co. (Union Carbide & Carbon Corp.) | Coatesville | PA |
| Linde Air Products Co. (Union Carbide & Carbon Corp.) | Duquesne | PA |
| Linde Air Products Co. (Union Carbide & Carbon Corp.) | Homestead | PA |
| Linde Air Products Co. (Union Carbide & Carbon Corp.) | Kittaning | PA |
| Linde Air Products Co. (Union Carbide & Carbon Corp.) | Pittsburgh | PA |
| LINDE AIR PRODUCTS COMPANY | KITTANNING | PA |
| LINDE AIR PROUDCTS COMPANY | DUQUESNE | PA |
| Linde Company | Erie | PA |
| Linde Company | Fairless Mills | PA |
| Linde Company | Farrell | PA |
| LINDNER SHOE COMPANY | CARLISLE | PA |
| LINDNER SHOE COMPANY | PHILADELPHIA | PA |
| Line Company | Braddock | PA |
| LINK BELT COMPANY | COLMAR | PA |
| Link Belt Engineering Co. | Philadelphia | PA |
| LINK BELT ENGINEERING COMPANY | PHILADELPHIA | PA |
| LINK BELT ENGINEERING COMPANY, BY DODGE AND DAY | NICETOWN, PHILADELPHIA | PA |
| LIQUID CARBONIC ACID MANUFACTURING COMPANY | PITTSBURGH | PA |
| LIQUID CARBONIC CORPORATION | PHILADELPHIA | PA |
| Little Sisters of the Poor | Pittsburgh | PA |
| Locher’S Green House | West View | PA |
| LOCHIEL ROLLING MILL COMPANY | HARRISBURG | PA |
| LOCKHART IRON AND STEEL COMPANY | MCKEES ROCKS | PA |
| LOCUST SPRING COLLIERY | LOCUST GAP | PA |
| LOEWENGART & CO. INC. – Mercersburg Tannery Div. | MERCERSBURG | PA |
| LOFTUS ENGINEERING CO | PITTSBURGH | PA |
| Loftus Engineering Corporation | Pittsburgh | PA |
| LOGAN IRON AND STEEL COMPANY | BURNHAM | PA |
| LOGAN IRON AND STEEL COMPANY | LEWISTOWN | PA |
| LONE STAR CEMENT | NAZARETH | PA |
| LONE STAR CEMENT CORP | NAZARETH | PA |
| LONE STAR INDUSTRIES INC | NAZARETH | PA |
| Long Publishing Company | Philadelphia | PA |
| LONGMEAD IRON COMPANY | CONSHOHOCKEN | PA |
| Long’S P & H Service | Easton | PA |
| LONGSTRETH ELEMENTARY SCHOOL – 57TH & WILLOW AVENUE | PHILADELPHIA | PA |
| LOOS & DILWORTH | PHILADELPHIA | PA |
| LOOSE WILES BISCUIT COMPANY | PITTSBURGH | PA |
| LORAIN STEEL COMPANY | JOHNSTOWN | PA |
| LORAIN STEEL COMPANY | JOHNSTON | PA |
| LORAINE STEEL | JOHNSTOWN | PA |
| LOREN’S HEAT TREATING | PHILADELPHIA | PA |
| LORENZ & SONS | PHILADELPHIA | PA |
| LORENZ HEAT TREATING | PHILADELPHIA | PA |
| LORMACK CORPORATION | SCHELLBURG | PA |
| Louis B. Orlowitz Plumbing Supply | Philadelphia | PA |
| LOUIS E. DIERUFF JUNIOR HIGH SCHOOL | ALLENTOWN | PA |
| LOUIS KRAEMER AND COMPANY | READING | PA |
| LOU’S BAR | PHILADELPHIA | PA |
| LOVEKIN TRAGESER DIV | PHILADELPHIA | PA |
| LOVEKIN WATER HEATER COMPANY – HOME OFFICE | PHILADELPHIA | PA |
| LOVELL COAL MINING COMPANY | PORTAGE | PA |
| LOVELL MFG CO | ERIE | PA |
| LOWER MERION HIGH SCHOOL | ARDMORE | PA |
| LOWER WORKS | WOODLAND | PA |
| L’SONNEBARN SONS INCORPORATED | PETROLIA | PA |
| LTV SHEET AND TUBE | MIDLAND | PA |
| LTV Steel | Aliquippa | PA |
| LTV Steel | Rochester | PA |
| LTV Steel | Monaca | PA |
| LTV Steel | Baden | PA |
| LTV Steel | Ambridge | PA |
| LTV STEEL | PITTSBURGH | PA |
| LTV STEEL – COKE PLANT | PITTSBURGH | PA |
| LTV STEEL – HAZELWOOD PLANT | PITTSBURGH | PA |
| LTV STEEL – SOUTHSIDE | PITTSBURGH | PA |
| LTV Steel (fka J&L / Republic) – Hazelwood | PITTSBURGH | PA |
| LTV Steel (fka J&L Steel) | ALIQUIPPA | PA |
| LTV Steel (fka J&L Steel) – South Side Plant | PITTSBURGH | PA |
| LTV, f/k/a J&L STEEL | ALIQUIPPA | PA |
| LUCENT TECHNOLOGIES, INCORPORATED | ALLENTOWN | PA |
| LUCENT TECHNOLOGIES, INCORPORATED | BREINIGSVILLE | PA |
| LUCENT TECHNOLOGOES | READING | PA |
| Lucerne Mines | Indiana | PA |
| LUCIFER FURNACES | WARRINGTON | PA |
| LUCY FURN | PITTSBURGH | PA |
| LUCY FURNACES | PITTSBURGH | PA |
| LUDLOW ELEMENTARY SCHOOL – 6TH & MASTER STREETS | PHILADELPHIA | PA |
| LUKE FIDLER COLLIERY | SHAMOKIN | PA |
| LUKENS IRON AND STEEL COMPANY | COATESVILLE | PA |
| Lukens Steel | Coatesville | PA |
| Lukens Steel | Coatsville | PA |
| Lukens Steel Co | Coatesville | PA |
| LUKENS STEEL CO | COATSVILLE | PA |
| LUKENS STEEL CO. – PHYSICAL TEST LABS. | COATESVILLE | PA |
| Lukens Steel Company | Coatesville | PA |
| LUKENS STEEL CORP | COATESVILLE | PA |
| LUKENS STEEL PLANT | COATESVILLE | PA |
| Lumax Industries | Altoona | PA |
| LUPTON MFG CO | PHILADELPHIA | PA |
| Luzerne County Gas & Electric | Humlock Creek | PA |
| LYCOMING EDISON COMPANY | WILLIAMSPORT | PA |
| LYCOMING ELECTRIC COMPANY – POWER PLANT | WILLIAMSPORT | PA |
| Lycoming Rubber Co. | Williamsport | PA |
| LYKENS VALLEY COAL COMPANY | LYKENS VALLEY | PA |
| LYKENS VALLEY COAL COMPANY | LYKENS | PA |
| LYNN HEIDELBERG SCHOOL | NEW TRIPOLI | PA |
| LYNN HEIDELBERG SCHOOL | TRIPOLI | PA |
| LYNNEWOOD GARDENS | ELKINS PARK | PA |
| LYTLE COAL COMPANY | PRIMROSE | PA |
| LYTLE COAL COMPANY | MINERSVILLE | PA |
| M & G Industrial Associates, Inc. | Pittsburgh | PA |
| M MILLER SPRING & MFG CO | PITTSBURGH | PA |
| M S A RESEARCH CORP | CALLERY | PA |
| M S A RESEARCH CORP | GALLERY | PA |
| M Schnoll & Sons | Philadelphia | PA |
| M. AND M. MARS, INCORPORATED | ELIZABETHTOWN | PA |
| M. AND W.H. NIXON | PHILADELPHIA | PA |
| M. AND W.H. NIXON, EAST MANAYUNK | PHILADELPHIA | PA |
| M. AND W.H. NIXON, PAPER COMPANY | PHILADELPHIA | PA |
| M. L. Clothier | Villa Nova | PA |
| M. S. A. RESEARCH CENTER | CALLERY | PA |
| M.H. PICKERING | PITTSBURGH | PA |
| M.L. BAYARD AND COMPANY | PHILADELPHIA | PA |
| M.T. SEAKITE | CHESTER | PA |
| M.W. KELLOGG | WILLIAMSPORT | PA |
| MABEL FURNACE | SHARPSVILLE | PA |
| Mac Service, Incorporated | Windber | PA |
| MACAW BROTHERS | NORWOOD | PA |
| MACAW BROTHERS | NORWOOD STATION | PA |
| MAC-CO SERVICE | PITTSBURGH | PA |
| MACHINE SHOP | ALTOONA | PA |
| MACHOLD AND RIDDELL | PHILADELPHIA | PA |
| MACK AXE WORKS | BEAVER FALLS | PA |
| MACK MFG. CORP. | ALLENTOWN | PA |
| Mack Truck | Allentown | PA |
| MACK TRUCK | MACKUNGIE | PA |
| MACK TRUCKS – WORLD HEADQUARTERS – MACK BOULEVARD | ALLENTOWN | PA |
| MACK WAREHOUSE | PHILADELPHIA | PA |
| MACK WAREHOUSE CORP. | PHILADELPHIA | PA |
| MACK WHSE. | PHILADELPHIA | PA |
| Mackintosh Hemphill | Midland | PA |
| MACKINTOSH HEMPHILL AND COMPANY | PITTSBURGH | PA |
| MACKINTOSH-HEMPHILL | MIDLAND | PA |
| MACKINTOSH-HEMPHILL | PITTSBURGH | PA |
| Mackintosh-Hemphill Company | Pittsburgh | PA |
| MADDOCK & CO | BALA CYNWYD | PA |
| Magazine Lumber Co | Cardale | PA |
| MAGEE CARPET CO | BLOOMSBURG | PA |
| MAGEE CARPET CO – PIPE SHOP | BLOOMSBURG | PA |
| MAGEE CARPET CO. | BLOOMSBURG | PA |
| Magee Carpet Company | Bloomsburg | PA |
| MAGEE CARPET COMPANY – BLDG 50 | BLOOMSBURG | PA |
| MAGEE GENERAL HOSPITAL | PITTSBURGH | PA |
| MAGEE WOMENS HOSPITAL | PITTSBURGH | PA |
| MAGINN AND LEWIS | PITTSBURGH | PA |
| MAHONING ROLLING MILL COMPANY | DANVILLE | PA |
| MAHONING VALLEY IRON COMPANY | PITTSBURGH | PA |
| MAHONINGTOWN SHOPS | NEW CASTLE | PA |
| MAJESTIC APARTMENT HOUSE | PHILADELPHIA | PA |
| Makefield Elementary | Yardley | PA |
| MALL OFFICE BUILDING | PHILADELPHIA | PA |
| MALSBARY MANUFACTURING CO | UNIONTOWN | PA |
| MALTHBY COLLIERY | WYOMING | PA |
| MAMMOTH SHAFT MINE – MAMMOTH PLANT | MAMMOTH | PA |
| MANAYUNK | PHILADELPHIA | PA |
| MANGANESE STEEL FORGE CO | PHILADELPHIA | PA |
| Manganese Steel Forge Co. | Philadelphia | PA |
| MANHATTAN SLATE COMPANY | SLATINGTON | PA |
| MANITOWOC (USS) | PHILADELPHIA | PA |
| MANN BROTHERS | HARRISBURG | PA |
| MANOR BRICK CRAFTERS INC | NEW OXFORD | PA |
| MANOR OAK TWO – COCHRAN ROAD | PITTSBURGH | PA |
| MANUFACTURERS LIGHT AND HEAT PLANT | CLAYSVILLE | PA |
| Maple Avenue Hospital | Du Bois | PA |
| MARATHON CO | LESTER | PA |
| MARCAL PAPER MILLS, INCORPORATED | PHILADELPHIA | PA |
| MARCK SHARP & DOHME INC – H. K. Mulford Plant | PHILADELPHIA | PA |
| MARCUS HOOK PLANT | MARCUS HOOK | PA |
| Marietta Carpet Plant | Marietta | PA |
| MARIETTA METAL PRODUCTS CORP. | MARIETTA | PA |
| MARIETTA METAL PRODUCTS CORP. | PHILADELPHIA | PA |
| MARINE BANK BUILDING – STATE STREET | ERIE | PA |
| MARINE CORPS RECRUITING DEPOT | WEST READING | PA |
| MARINE LEADER | CHESTER | PA |
| MARITIME SUPPLY CO | PHILADELPHIA | PA |
| MARKER & SONS | MC KEESPORT | PA |
| MARKER & SONS | MCKEESPORT | PA |
| Marks & Wyant Plumbing & Heating | Chalfont | PA |
| MARKS BROTHERS | PHILADELPHIA | PA |
| Marlsbary Mfg Co | Uniontown | PA |
| MARPLE TOWNSHIP | DELAWARE COUNTY | PA |
| MARQUETTE CEMENT | PITTSBURGH | PA |
| MARQUETTE CEMENT | NEVILLE ISLAND | PA |
| MARQUETTE CEMENT – NEVILLE ISLAND | PITTSBURGH | PA |
| Marquette Cement Mfg. Co. | Neville Township | PA |
| MARSDEN T J CO | POTTSVILLE | PA |
| MARSH PLATE GLASS COMPANY | WALTON | PA |
| MARSHALL BROTHERS AND COMPANY | PHILADELPHIA | PA |
| MARSHALL BROTHERS AND COMPANY | NEWPORT | PA |
| MARSHALL KENNEDY COMPANY | PITTSBURGH | PA |
| MARSHALL KENNEDY COMPANY | ALLEGHENY | PA |
| MARSHALSEA FOUR ARM | PITTSBURGH | PA |
| MARTIN AND W.H. NIXON | EAST MANAYUNK | PA |
| MARTIN AND W.H. NIXON | PHILADELPHIA | PA |
| MARTIN AND WILLIAM H. NIXON PAPER COMPANY | PENEOYD | PA |
| MARTIN AND WILLIAM NIXON PAPER COMPANY | PENCOYD | PA |
| MARTIN LUTHER KING HIGH SCHOOL – STENTON AVENUE | PHILADELPHIA | PA |
| MARTIN LUTHER KING JUNIOR SCHOOL | PHILADELPHIA | PA |
| MARTIN LUTHER KING SCHOOL – STENTON AVENUE & HAINES STREET | PHILADELPHIA | PA |
| MARTIN TOWERS | BETHLEHEM | PA |
| MARTINS CREEK | MARTINS CREEK | PENNSYLVANIA |
| MARTINS CREEK POWER STATION | MARTINS CREEK | PA |
| Martins Creek Powerhouse | Martins Creek | PA |
| MARTINS CREEK, P.P.L. | STROUDSBURG | PA |
| Mary Immaculate Seminary | Northampton | PA |
| MARY STREET PROJECT | KINGSTON | PA |
| MARY WOOD COLLEGE – NEW BOILER ROOM | SCRANTON | PA |
| MARY WOOD COLLEGE – NOVITIATE BLDG | SCRANTON | PA |
| MARYLAND COAL COMPANY | SOUTH FORK | PA |
| MARYLAND COAL COMPANY | HAZELTON | PA |
| MARYLAND COAL COMPANY | PHILADELPHIA | PA |
| MARYLAND COAL COMPANY | TUSCARORA | PA |
| MARYLAND COAL COMPANY | MARYD | PA |
| MARYLAND COAL COMPANY OF PENNSYLVANIA | ST. MICHAEL | PA |
| MARYLAND STEEL COMPANY | PHILADELPHIA | PA |
| MARYWOOD UNIVERSITY – MARIAN CONVENT BUILDING – ADAMS AVENUE | SCRANTON | PA |
| MASLAND DURALEATHER CO | PHILADELPHIA | PA |
| MASONIC HOMES – NEW RECREATION BLDG. | ELIZABETHTOWN | PA |
| MASONIC HOMES – RECREATION BLDG. | ELIZABETHTOWN | PA |
| Masonic Temple | Pottstown | PA |
| MASONRY INC | CARNEGIE | PA |
| Masontown Brewing Co. | Masontown | PA |
| Masontown Bridge, Hatfield Power Station | Monongahela | PA |
| Masontown Bridge, Hatfield Power Station | Masontown | PA |
| MATHER CO. | TOLEDO | PA |
| MATHER COLLIERIES | RICES LANDING | PA |
| MATTHEW S. LEWIS COMPANY | CANONSBURG | PA |
| MATTHIESSEN AND HEGELER ZINC COMPANY | ELRAMA | PA |
| MAUCH CHUNK CRYSTAL ICE COMPANY | MAUCH CHUNK | PA |
| MAUCH CHUNK LEHIGHTON AND SLATINGTON RAILWAY COMPANY | MAUCH CHUNK | PA |
| MAUCH CHUNK LEHIGHTON AND SLATINGTON RAILWAY COMPANY | ALLENTOWN | PA |
| MAUMEE (USS) | CHESTER | PA |
| MAX AND LEVY BUILDING | PHILADELPHIA | PA |
| Max Brockton Textile Company | Philadelphia | PA |
| MAXTON | CHESTER | PA |
| MAXWELL COLLIERY | ASHLEY | PA |
| MAXWELL COLLIERY, #20 | ASHLEY | PA |
| MAYER CHINA COMPANY | BEAVER FALLS | PA |
| MC AVEY BRICK CO | PHOENIXVILLE | PA |
| MC CLASKEY & CO | PHILADELPHIA | PA |
| MC CONWAY & FORLEY CORP | PITTSBURGH | PA |
| MC CONWAY & TURLEY CORP | PITTSBURGH | PA |
| MC CULLOUGH IRON COMPANY | PHILADELPHIA | PA |
| MC CUSKER T J INC | W MIFFLIN | PA |
| MC CUSKER T J INC | W. MIFFLIN | PA |
| MC DANIEL AND HARVEY | PHILADELPHIA | PA |
| MC DOWELL PAPER COMPANY | MANAYUNK | PA |
| Mc Kay Co | York | PA |
| Mc Keesport Coating Co | Mc Keesport | PA |
| MCARDLE & COONEY INC. | PHILADELPHIA | PA |
| MCCAHAN SUGAR COMPANY | PHILADELPHIA | PA |
| MCCAHAN SUGAR REFINING AND MOLASSES COMPANY | PHILADELPHIA | PA |
| McCann Shields Paint Co. | Pittsburgh | PA |
| Mccarter Iron | Norristown | PA |
| MCCARTER IRON WORKS | MORRISTOWN | PA |
| MCCARTER IRON WORKS | NORRISTOWN | PA |
| MCCLAIR, BROOKS AND COMPANY | SCRANTON | PA |
| MCCLASKEY & CO | PHILIDELPHIA | PA |
| MCCLASKEY & CO | PHILADELPHIA | PA |
| MCCLAVE BROOKS AND COMPANY | SCRANTON | PA |
| MCCLELLAN STORAGE YARD | MCCLELLAN | PA |
| MCCLINTIC-MARSHALL CONSTRUCTION COMPANY – STEEL PLANT | POTTSTOWN | PA |
| MCCLINTIC-MARSHALL CONSTRUCTION COMPANY – STEEL PLANT | CARNEGIE | PA |
| MCCLOSKEY VARNISH COMPANY | PHILADELPHIA | PA |
| MCCLURE COMPANY | WASHINGTON | PA |
| MCCONNELL ASBESTO AND COVERING COMPANY | ETNA | PA |
| McConnellsburg Medical Center | McConnellsburg | PA |
| MCCONOVAY AND TORLEY CORP | PITTSBURG | PA |
| MCCONOVAY AND TORLEY CORP | PITTSBURGH | PA |
| MCCONWAY & TORLEY CORP | PITTSBURGH | PA |
| MCCONWAY AND FORLEY COMPANY | PITTSBURGH | PA |
| MCCONWAY AND TORLEY CORPORATION | PITTSBURGH | PA |
| MCCONWAY-TORLEY | PITTSBURGH | PA |
| MCCRACKEN STARK AND COMPANY | PHILADELPHIA | PA |
| MCCREARY TIRE & RUBBER CO | INDIANA | PA |
| MCDOWELL PAPER MILLS | MANAYUNK | PA |
| McEnery Co. | Erie | PA |
| MCFADDEN JAMES E INC | PHILADELPHIA | PA |
| MCGRAW EDISON COMPANY | PITTSBURGH | PA |
| MCGRAW EDISON COMPANY – POWER SYSTEMS DIV | CANONSBURG | PA |
| Mcgraw-Edison | Canonsburg | PA |
| McGraw-Edison Power Systems | Canonsburg | PA |
| MCGREW PARKINSON AND COMPANY | MONONGAHELA | PA |
| MCGUINNES COMPANY | PITTSBURGH | PA |
| MCKAY CORPORATION | YORK | PA |
| MCKEAN OIL PLANT | FARMERS VALLEY | PA |
| MCKEAN, NEWHALL AND BORIE | PHILADELPHIA | PA |
| MCKEE DIVISION | JEANNETTE | PA |
| MCKEES ROCKS IND ENTERPRISES – BLDG 45 | MCKEES ROCKS | PA |
| MCKEESPORT AND YOUGHIOGHENY ICE COMPANY | MCKEESPORT | PA |
| MCKEESPORT BOARD OF WATER AND LIGHTING – PUMPING STATION | MCKEESPORT | PA |
| McKeesport Hospital | Pittsburgh | PA |
| MCKEESPORT HOSPITAL | MCKEESPORT | PA |
| MCKEESPORT MANUFACTURING COMPANY | MCKEESPORT | PA |
| MCKEESPORT TIN PLATE COMPANY | MCKEESPORT | PA |
| MCKEESPORT WATER PURIFICATION WORKS | MCKEESPORT | PA |
| MCKEESPORT WORKS | MCKEESPORT | PA |
| MCKINLEY ELEMENTARY SCHOOL | YORK | PA |
| MCKINNEY MANUFACTURING COMPANY | ALLEGHENY | PA |
| McLanahan Corp. | Hollidaysburg | PA |
| MCLAUGHLIN BROTHERS | PHILADELPHIA | PA |
| MCLEAN NEWHALL AND BORIE | PHILADELPHIA | PA |
| MEADOWVALE SCHOOL, MESSENGER ST. | JOHNSTOWN | PA |
| MEADVILLE FORGING CO | MEADVILLE | PA |
| MEATA MACHINE CO | NEW CASTLE | PA |
| Mechanical Insulation Co | Lester | PA |
| Mechanical Insulation Co | Philadelphia | PA |
| Mechanical Insulation Co | Plymouth Meeting | PA |
| MECHANICAL INSULATION CO. | LESTER | PA |
| Mechanical Insulation Company | Philadelphia. Pa & Lester | PA |
| Mechanicsburg Navy Depot | Mechanicsburg | PA |
| Medal Distributing Co | Sharon | PA |
| MEDFORD’S INC. | CHESTER | PA |
| MEDICAL PAVILION – HOSPITAL | PITTSBURGH | PA |
| MEDIUM VOLTAGE SWGR. DEPARTMENT | PHILADELPHIA | PA |
| Medusa Cement Co., Division of Medusa Corp – Wampum Plant | Wampum | PA |
| Medusa Cement Company | York | PA |
| MEDUSA PORTLAND CEMENT | WAMPUN | PA |
| MEDUSA PORTLAND CEMENT CO | WEST YORK | PA |
| MEDUSA PORTLAND CEMENT COMPANY | WEST YORK | PA |
| MEDUSA PORTLAND CEMENT COMPANY | WAMPUM | PA |
| MEDUSA PORTLAND CEMENT COMPANY | YORK | PA |
| MEGARGEE PAPER COMPANY | EDGELY | PA |
| MEGARGEE PAPER MILLS | TULLYTOWN | PA |
| MEILI & WORTHINGTON | HATBORO | PA |
| MELLON BANK, OLD USS BUILDING | PITTSBURGH | PA |
| Mellon Institute of Industrial Research | Pittsburgh | PA |
| MELLON INSTITUTE OF INDUSTRIAL RESEARCH BUILDING | PITTSBURGH | PA |
| MELVILLE CORBETT COMPANY | KAULMONT, ELK COUNTY | PA |
| Memorial Hospital – Boiler Room Ceiling | Johnstown | PA |
| MENS HOUSE OF DETENTION | PHILADELPHIA | PA |
| Mercer Alloys | Greenville | PA |
| MERCER COUNTY COURT HOUSE | MERCER | PA |
| MERCER COUNTY LIGHT COMPANY – POWER PLANT | GREENVILLE | PA |
| MERCER LIME & STONE CO | PITTSBURGH | PA |
| MERCER LIME AND STONE CO | PITTSBURGH | PA |
| MERCHANT SHIPBUILDING CORPORATION | BRISTOL | PA |
| MERCHANTS COAL COMPANY | BOSWELL | PA |
| MERCHANTS COAL COMPANY | STOYESTOWN | PA |
| MERCHANTS COAL COMPANY OF PENNSYLVANIA | BOSWELL | PA |
| MERCHANTS SHIP BUILDING CORPORATION | BRISTOL | PA |
| Merck & Co. | Danville | PA |
| Merck & Company, Inc. | Riverside | PA |
| Merck And Company | Riverside | PA |
| Merck And Company | Danville | PA |
| MERCK AND COMPANY | LANSDALE | PA |
| MERCK AND COMPANY | WEST POINT | PA |
| MERCK AND COMPANY PLANT | DANVILLE | PA |
| MERCK AND COMPANY, BUILDING #2 | WEST POINT | PA |
| MERCK AND COMPANY, INCORPORATED | WEST POINT | PA |
| MERCK AND COMPANY, INCORPORATED | RIVERSIDE BOROUGH | PA |
| Merck Chemical | Danville | PA |
| MERCK SHARPE & DOHME | WEST POINT | PA |
| MERCK SHARPE & DOHME – BUILDING 65 – CAT HOME | WEST POINT | PA |
| MERCK SHARPE & DOHME, BUILDING 65, CAT HOME | WEST POINT | PA |
| MERCK, SHARP AND DOHME | WEST POINT | PA |
| Merck, Sharpe and Dohme | West Point | PA |
| MERCY HOSPITAL | PITTSBURGH | PA |
| MERCY HOSPITAL | ALTOONA | PA |
| Mercy-Douglass Hospital | Philadelphia | PA |
| MERION AND RADNOR GAS AND ELECTRIC COMPANY – POWER PLANT | WAYNE | PA |
| MERMOUNT GARDENS | BRYN MAWR | PA |
| MERRICK CHEMICAL PLANT | DANVILLE | PA |
| MERRITT CHAPMAN & SCOTT | MILTON | PA |
| Messinger Bearings, Inc. | Philadelphia | PA |
| Mesta Machine | Homestead | PA |
| MESTA MACHINE CO | HOMESTEAD | PA |
| MESTA MACHINE CO | ALL PA LOCATIONS | PA |
| MESTA MACHINE CO | NEW CASTLE | PA |
| MESTA MACHINE CO (a/k/a United Engineering & Foundry Co.) | NEW CASTLE | PA |
| MESTA MACHINE CO (a/k/a United Engineering & Foundry Co.) | PITTSBURGH | PA |
| Mesta Machine Co. | Pittsburg/Homestead | PA |
| MESTA MACHINE CO. | HOMESTEAD | PA |
| Mesta Machine Company | Homestead | PA |
| Mesta Machine Company | Pittsburgh | PA |
| MESTA MACHINE CORP | HOMESTEAD | PA |
| MESTA MACHINE CORP | NEW CASTLE | PA |
| METAL BANK OF AMERICA | PHILADELPHIA | PA |
| METAL TREATING CO | PITTSBURGH | PA |
| METHACTON HIGH SCHOOL | FAIRVIEW VILLAGE | PA |
| METHODIST TOWERS – WEST 8TH STREET | ERIE | PA |
| Metropolital Edision | Williamsburg | PA |
| Metropolital Edision | Homer City | PA |
| Metropolitan Edison – G.E. Titus Station Turbine | Philadelphia | PA |
| METROPOLITAN EDISON – THREE MILE ISLAND NUCLEAR GENERATING STATION | MIDDLETOWN | PA |
| METROPOLITAN EDISON – THREE MILE ISLAND NUCLEAR GENERATING STATION – UNIT 1 | MIDDLETOWN | PA |
| METROPOLITAN EDISON – YORK HAVEN PLANT | YORK | PA |
| Metropolitan Edison Co | Reading | PA |
| Metropolitan Edison Co | Middletown | PA |
| METROPOLITAN EDISON CO – EYLER STATION STOREHOUSE | WEST READING | PA |
| METROPOLITAN EDISON CO – PORTLAND GENERATING STATION | PORTLAND | PA |
| METROPOLITAN EDISON CO – PORTLAND GENERATING STATION – UNIT #1 | PORTLAND | PA |
| METROPOLITAN EDISON CO – PORTLAND GENERATING STATION – UNIT #2 | PORTLAND | PA |
| METROPOLITAN EDISON CO – PORTLAND GENERATING STATION BETHEL TWP | PORTLAND | PA |
| METROPOLITAN EDISON CO – PORTLAND GENERATING STATION UNIT 2 | PORTLAND | PA |
| METROPOLITAN EDISON CO – TITUS STATION | READING | PA |
| METROPOLITAN EDISON CO – TITUS STATION – PLANT SUPERINTENDENT | READING | PA |
| METROPOLITAN EDISON CO – UNIT #1 | PORTLAND | PA |
| Metropolitan Edison Co. – Titus Station | Reading | PA |
| Metropolitan Edison Co.- Portland Generating Station | Portland | PA |
| Metropolitan Edison Co., Titus Station | Reading | PA |
| Metropolitan Edison Company | Williamsburg | PA |
| Metropolitan Edison Company | Homer City | PA |
| Metropolitan Edison Company | Reading | PA |
| METROPOLITAN EDISON COMPANY | PORTLAND | PA |
| METROPOLITAN EDISON COMPANY | UPPER MOUNT BETHEL | PA |
| METROPOLITAN EDISON COMPANY | WEST READING | PA |
| METROPOLITAN EDISON COMPANY – GENERATING STATION | READING | PA |
| Metropolitan Edison Company – Portland Generating Station | Mt. Bethel | PA |
| METROPOLITAN EDISON COMPANY – PORTLAND POWER PLANT | UPPER MOUNT BETHEL | PA |
| METROPOLITAN EDISON COMPANY – PORTLAND STATION | PORTLAND | PA |
| METROPOLITAN EDISON COMPANY – THREE MILE ISLAND | MIDDLETOWN | PA |
| Metropolitan Edison Company – Titus Station | Reading | PA |
| METROPOLITAN EDISON COMPANY – TURBINE REPAIR | PHILADELPHIA | PA |
| METROPOLITAN EDISON COMPANY, DOCK ST. STATION | EASTON | PA |
| METROPOLITAN EDISON COMPANY, PORTLAND STATION | PORTLAND | PA |
| METROPOLITAN EDISON COMPANY, THREE MILE ISLAND | MIDDLETOWN | PA |
| METROPOLITAN EDISON COMPANY, TITUS STATION | READING | PA |
| METROPOLITAN EDISON POWER – BRUNNERS ISLAND | YORK HAVEN | PA |
| Metropolitan Edison Power Plant | Portland | PA |
| METROPOLITAN EDISON-TMI | HARRISBURG | PA |
| METROPOLITAN HOSPITAL – 8TH & RACE STREETS | PHILADELPHIA | PA |
| MEYER ZAUSNER INC | NEW HOLLAND | PA |
| MEYERSDALE JR.-SR. HIGH SCHOOL | MEYERSDALE | PA |
| MICHAEL FLYNN | PHILADELPHIA | PA |
| MICHAEL FLYNN MFG | PHILADELPHIA | PA |
| MICHIGAN CHEMICAL COMPANY | PITTSBURGH | PA |
| Michigan Limestone And Chemical | Annandale | PA |
| MIDDLE CREEK ELECTRIC COMPANY – POWER PLANT | NORTHUMBERLAND | PA |
| MIDDLE SCHOOL – ROUTE 30 | IMPERIAL | PA |
| MIDDLETOWN CAR COMPANY | MIDDLETOWN | PA |
| MIDDLETOWN CAR WORKS | MIDDLETOWN | PA |
| MIDDLETOWN ELEM. SCHOOL | LANGHORN | PA |
| MIDDLETOWN ELEM. SCHOOL | MIDDLETOWN TWSHP. | PA |
| MIDDLETOWN ELEMENTARY SCHOOL | MIDDLETOWN | PA |
| MIDDLETOWN SCHOOL | BORNSTEIN | PA |
| Midland Ross | Sharon | PA |
| MIDLAND STEEL COMPANY | MIDLAND | PA |
| MIDLAND WORKS | MIDLAND | PA |
| MIDLAND-ROSS CORP | PITTSBURGH | PA |
| MIDUALE-HEPPENSTAHL | PHILADELPHIA | PA |
| MIDVALE COMPANY | NICETOWN, PHILADELPHIA | PA |
| MIDVALE COMPANY | PHILADELPHIA | PA |
| MIDVALE HEPPENSTALL CO | NICETOWN PHIL | PA |
| MIDVALE HEPPENSTALL COMPANY | EDDYSTONE | PA |
| MIDVALE HEPPENSTALL COMPANY | PHILADELPHIA | PA |
| MIDVALE HEPPENSTALL COMPANY | NICETOWN, PHILADELPHIA | PA |
| Midvale Steel | Nicetown | PA |
| MIDVALE STEEL AND ORDNANCE COMPANY | NICETOWN | PA |
| MIDVALE STEEL AND ORDNANCE COMPANY | PHILADELPHIA | PA |
| MIDVALE STEEL COMPANY | PHILADELPHIA | PA |
| MIDVALE STEEL COMPANY | NICETOWN | PA |
| MIDVALEE HEPPENSTALL COMPANY | NICETOWN, PHILADELPHIA | PA |
| MIDVALLEY COAL COMPANY | PHILADELPHIA | PA |
| MIDVALLEY COAL COMPANY | WILBURTON | PA |
| MIDVALLEY COAL COMPANY | CENTRALIA | PA |
| MIDVALLEY COAL COMPANY | MAUCH CHUNK | PA |
| MIDVALLEY COAL COMPANY | MT. CARMEL | PA |
| MIDVALLEY COAL COMPANY | CENTRALIA STATION | PA |
| MIDVALLEY COAL COMPANY | WILLBURTON | PA |
| MIDWEST GENERATION – HOMER CITY GENERATION STATION | HOMER CITY | PA |
| MILBON MANUFACTURING COMPANY | MILBON | PA |
| MILCO UNDERGARMENT CO. | BLOOMSBURG | PA |
| Milesburg Power Plant | Milesburg | PA |
| MILL #4 | MARTINS CREEK | PA |
| MILL CREEK COAL COMPANY | NEW BOSTON | PA |
| MILL CREEK COAL COMPANY | DELANO | PA |
| MILL CREEK COAL COMPANY | VULCAN | PA |
| MILL CREEK POWER HOUSE | JOHNSTOWN | PA |
| MILL CREEK SCHOOL | ERIE | PA |
| Millard Quarry | Annville | PA |
| MILLBOURNE MILLS | PHILADELPHIA | PA |
| Millcreek Mall | Erie | PA |
| MILLER GAS & OIL | SHAMOKIN | PA |
| MILLER PLANNER BLDG | MARKLEYSBURG | PA |
| MILLER PLANNER BLDG – AUXILIARY BOILER | MARKLEYSBURG | PA |
| Miller Printing Machinery Company | Pittsburgh | PA |
| MILLER QUARRIES INC. | RUSHLAND | PA |
| MILLER ROBERT L | MECHANICSBURG | PA |
| MILLERSVILLE UNIVERSITY – ARTS BUILDING | MILLERSVILLE | PA |
| MILLERSVILLE UNIVERSITY – WOMEN’S DORM | MILLERSVILLE | PA |
| MILLIAM A COLLIERY LIGHT AND POWER | JUNCTION | PA |
| MILLIKEN HOSPITAL BOILER ROOM | POTTSVILLE | PA |
| MILTON MANUFACTURING | MILTON | PA |
| MILTON MANUFACTURING CO. | MILTON | PA |
| MILTON MANUFACTURING COMPANY | MILTON | PA |
| Minard Run Oil Company | Bradford | PA |
| MINE SAFETY APPLIANCE CO | CALLERY | PA |
| MINE SAFETY APPLIANCE CO | PITTSBURGH | PA |
| MINE SAFETY APPLIANCE CO | PHILADELPHIA | PA |
| MINE SAFETY APPLIANCE COMPANY | PITTSBURGH | PA |
| MINE SAFETY APPLIANCES CO | PITTSBURGH | PA |
| MINE SAFETY APPLIANCES CO – ATEC BLDG. | PITTSBURGH | PA |
| MINERAL RAILROAD AND MINING COMPANY | SHAMOKIN | PA |
| MINERAL RAILROAD AND MINING COMPANY | WILKES BARRE | PA |
| MINERAL SPRING COLLIERY | WILKES BARRE | PA |
| MINNEPOLIS HONEYWELL REG. CO. – BROWNS INSTRUMENT DIVISION | PHILADELPHIA | PA |
| Minnesota Mining & Manufacturing Company | Bristol | PA |
| Minnesota Mining and Manufacturing Co | Bristol | PA |
| MINNOTTE MFG CORP | PITTSBURGH | PA |
| MINOTTE BROTHERS COMPANY | PITTSBURGH | PA |
| Mira Bell, Inc. | Philadelphia | PA |
| MISERACORDIA – STUDENT UNION & DORMS | KINGSTON | PA |
| MISSILE MASTER FACILITIES | OAKDALE | PA |
| Mitchell Power Station | Courtney | PA |
| Mitchell Power Station | Monongahela | PA |
| MITCHELL POWER STATION – WASHINGTON COUNTY | COURTNEY | PA |
| MITCHELL POWER STATION, WASHINGTON COUNTY | COURTNEY | PA |
| MITCHELL, FLETCHER AND COMPANY | PHILADELPHIA | PA |
| MOBAY CHEMICAL COMPANY | PITTSBURGH | PA |
| MOBIL | PHILADELPHIA | PA |
| MOBIL OIL CO | PHILADELPHIA | PA |
| Model Coat & Apron Co. | Pittsburgh | PA |
| MODEL LAUNDRY AND DRY CLEANING COMPANY | JEANNETTE | PA |
| MOE & CO A | PHILADELPHIA | PA |
| MOE A & CO | PHILADELPHIA | PA |
| MOHAWK VALLEY BREWING COMPANY | PHILADELPHIA | PA |
| Molded Materials Div., | Ridgway | PA |
| Monahan Insulation Company | Pittsburgh | PA |
| MONESSEN STEEL COMPANY | MONESSEN | PA |
| MONESSEN WORKS | MONESSEN | PA |
| MONONGAHELA CONNECTING RAILROAD COMPANY | PITTSBURGH | PA |
| MONONGAHELA ELECTRIC LIGHT COMPANY – LIGHT PLANT | MONONGAHELA | PA |
| MONONGAHELA FURNACE | MCKEESPORT | PA |
| MONONGAHELA FURNACES | MCKEESPORT | PA |
| MONONGAHELA INCLINE PLANE COMPANY | PITTSBURGH | PA |
| MONONGAHELA LIGHT AND POWER COMPANY | PITTSBURGH | PA |
| MONONGAHELA LIGHT AND POWER COMPANY | RANKIN | PA |
| MONONGAHELA MELTING COMPANY | ALTOONA | PA |
| MONONGAHELA POWER COMPANY | MASONTOWN | PA |
| Monongahela Railway | Brownsville | PA |
| MONONGAHELA RIVER CONSOLIDATED COAL AND COKE COMPANY | CALIFORNIA | PA |
| MONONGAHELA RIVER CONSOLIDATED COAL AND COKE COMPANY | PITTSBURGH | PA |
| MONONGAHELA STREET RAILWAY COMPANY | PITTSBURGH | PA |
| MONONGAHLEA ELECTRIC LIGHT AND POWER COMPANY – GAS AND ELECTRIC LIGHT PLANT | HOMESTEAD | PA |
| Monongalia & Ohio Dredging Company | Pittsburgh | PA |
| MONROE SHIP SUPPLY | PHILADELPHIA | PA |
| MONROEVILLE HIGH SCHOOL | MONROEVILLE | PA |
| Monroeville Mall | Monroeville | PA |
| MONROEVILLE MALL – GIMBELS DEPARTMENT STORE | MONROEVILLE | PA |
| MONSANTO CHEMICAL CO. | PHILADELPHIA | PA |
| Monsey Products | Kimberton | PA |
| Monsey Products | Wissahicken | PA |
| Monsey Products Company | Philadelphia | PA |
| MONT ALTO SANITARIUM | MONT ALTO | PA |
| MONTEFOIRE HOSPITAL | PITTSBURGH | PA |
| MONTGOMERY COUNTY COURTHOUSE | MORRISTOWN | PA |
| MONTGOMERY COUNTY COURTHOUSE – EAST AIRY STREET | NORRISTOWN | PA |
| MONTGOMERY IRON COMPANY | PORT KENNEDY | PA |
| MONTOUR | WASHINGTONVILLE | PENNSYLVANIA |
| MONTOUR CTY | DANVILLE | PA |
| Montour Power Plant | Washingtonville | PA |
| MONTOUR STEAM STATION-PA POWER & LIGHT | WASHINGTONVILLE | PA |
| MONTOUR STEEL AND IRON COMPANY | DANVILLE | PA |
| Moore Street Elementary School | Millersburg | PA |
| MOOREHEAD BROTHERS AND COMPANY | PITTSBURGH | PA |
| MOORHEAD BROTHERS | SHARPSBURG | PA |
| MOORHEAD BROTHERS AND COMPANY | SHARPSBURG | PA |
| MORADO | BEAVER COUNTY | PA |
| MORAVIAN COLLEGE | BETHLEHEM | PA |
| MORAVIAN COLLEGE, SCIENCE BUILDING | BETHLEHEM | PA |
| MORGAN PAPER COMPANY | LITITZ | PA |
| MORGANTHALER BROTHERS | PHILADELPHIA | PA |
| MORGENTHALER BROTHERS | PHILADELPHIA | PA |
| MORGENTHALER ICE MANUFACTURING COMPANY | PHILADELPHIA | PA |
| MORMACBAY | CHESTER | PA |
| MORMACCOVE | CHESTER | PA |
| MORMACLAKE | CHESTER | PA |
| MORMACPRIDE | CHESTER | PA |
| MORMACSCAN | CHESTER | PA |
| MORMACTRADE | CHESTER | PA |
| MORO PHILLIPS | PHILADELPHIA | PA |
| MORRELL FELIN MEAT PACKERS | PHILADELPHIA | PA |
| Morrellsville Colliery | Nantyglo | PA |
| MORRIS SCHOOL – 26TH & THOMPSON | PHILADELPHIA | PA |
| Morristown High School | PA | |
| MORRISVILLE HIGH SCHOOL | MORRISVILLE | PA |
| Moss Rehabilitation Hospital | Philadelphia | PA |
| Moss-Rose Manufacturing Company | Philadelphia | PA |
| Mother of Divine Grace | Philadelphia | PA |
| Motion Control (Molded Materials) | Ridgeway | PA |
| Motor Coils Mfg Co | Emporium | PA |
| Motor Coils Mfg Co | Evans City | PA |
| Motorola | Carlisle | PA |
| MOUNT ALTO SANITARIUM | MONT ALTO PARK | PA |
| MOUNT ALTO SANTARIUM | MONT ALTO PARK | PA |
| MOUNT HOLLY SPRINGS | CUMBERLAND COUNTY | PA |
| MOUNT JESSEYS COAL COMPANY | PECKVILLE | PA |
| MOUNT LEBANON HIGH SCHOOL – COCHRAN ROAD | MOUNT LEBANON | PA |
| MOUNT LEBANOUS ICE COMPANY | MT. LEBANON | PA |
| MOUNT LOOKOUT COAL COMPANY | WYOMING | PA |
| MOUNT MERCY COLLEGE – GRACE LIBRARY | PITTSBURGH | PA |
| MOUNT MORICH | PHILADELPHIA | PA |
| MOUNT PLEASANT ELECTRIC LIGHT AND POWER COMPANY – ELECTRIC LIGHT PLANT | MT. PLEASANT | PA |
| MOUNT SINAI HOSPITAL | PHILADELPHIA | PA |
| MOUNT ST. JOSEPH ACADEMY | PHILADELPHIA | PA |
| Mountain View Center, Inc. | Kylertown | PA |
| MRS PAUL`S FROZEN FOODS – TABOR ROAD | PHILADELPHIA | PA |
| Msa | Evans City | PA |
| MUHLENBERG COLLEGE – SHANKWEILER BIOLOGY BUILDING | ALLENTOWN | PA |
| MUHLENBERG HIGH SCHOOL | PHILADELPHIA | PA |
| MUHLENBURG COLLEGE – BIOLOGY LABORATORY | ALLENTOWN | PA |
| MULLIGAN HAROLD B | PHILADELPHIA | PA |
| MULLIGAN HAROLD R | PHILADELPHIA | PA |
| MULLINS MANUFACTURING CO | HAYS | PA |
| MUNCIPAL HOSPITAL | PHILADELPHIA | PA |
| MUNICIPAL HOSPITAL | PHILADELPHIA | PA |
| MUNICIPAL SERVICE BLDG CITY HALL | PHILADELPHIA | PA |
| MUNICIPAL SERVICES BUILDING | PHILADELPHIA | PA |
| Munition Plant | Tacony | PA |
| MURRAY BODY COMPANY | SCRANTON | PA |
| MURRAY CORPORATION | SCRANTON | PA |
| MUSKIN COAL MINING COMPANY | CAIRNBROOK | PA |
| MUSKIN MFG CO (a/k/a Wilkes Barre Lace Mfg) | WILKES BARRE | PA |
| MUSSER’S MARKET – FRIENDLY DRIVE | QUARRYVILLE | PA |
| MUTUAL CHEMICAL DIVISION OF ALLIED CHEMICAL AND DYE | PHILADELPHIA | PA |
| MUTUAL RENDERING CO | PHILADELPHIA | PA |
| MUTUAL SHOEMAKER CO | PHILADELPHIA | PA |
| N H Robertson Co | Ambridge | PA |
| N. AND G. TAYLOR COMPANY | PHILADELPHIA | PA |
| N. S. | PITTSBURGH | PA |
| N. SNELLENBURG AND COMPANY | PHILADELPHIA | PA |
| N.R.S. YEWDALL | PHILADELPHIA | PA |
| Nabisco | Philadelphia | PA |
| Nancy Corporation | Summerville | PA |
| Narco | Curwensville | PA |
| Narco | Womelsdorf | PA |
| NARCO PLANT – WOMELSDORF PLANT | WOMELSDORF | PA |
| NATHAN R. YEWDALL | PHILADELPHIA | PA |
| National Airoil Burner Co | Philadelphia | PA |
| NATIONAL ANILINE AND CHEMICAL COMPANY | MARCUS HOOK | PA |
| NATIONAL ANILINE DIVISION – USS CHEMICALS | MCKEES ROCKS | PA |
| NATIONAL BISCUIT COMPANY | PHILADELPHIA | PA |
| NATIONAL BISCUIT COMPANY | NORTH PHILADELPHIA | PA |
| NATIONAL BISCUIT COMPANY | EAST LIBERTY | PA |
| NATIONAL BISCUIT COMPANY | PITTSBURGH | PA |
| NATIONAL BISCUIT COMPANY – CRACKER BAKERY | PITTSBURGH | PA |
| National Biscuit Plant | Pittsburg | PA |
| NATIONAL BOND INSULATORS, INC. | ALLENTOWN | PA |
| NATIONAL BORAX COMPANY | LANCASTER | PA |
| NATIONAL CAN | FAIRLESS HILLS | PA |
| NATIONAL CASKET COMPANY, INCORPORATED | PITTSBURGH | PA |
| National Casting | Sharon | PA |
| NATIONAL CONTAINER COMPANY | BRISTOL | PA |
| NATIONAL CRICIBLE CO | PHILADELPHIA | PA |
| NATIONAL CRUCIBLE COMPANY | PHILADELPHIA | PA |
| NATIONAL DISTILLERS PRODUCTS CORPORATION | BROAD FORD | PA |
| NATIONAL DRUG CO – RESEARCH & DEVELOPMENT BLDG. | SWIFTWATER | PA |
| National Drug Co. – Manufacturing Plant | SWIFTWATER | PA |
| NATIONAL DRUG COMPANY | CENTER VALLEY | PA |
| NATIONAL DRYING MACHINE PLANT | PHILADELPHIA | PA |
| NATIONAL ELECTRIC PRODUCTS CO. | AMBRIDGE | PA |
| National Electric Products Company – Manufacturing Facility | Ambridge | PA |
| NATIONAL ELECTRIC PRODUCTS CORP | AMBRIDGE | PA |
| NATIONAL FOAM CO | WEST CHESTER | PA |
| NATIONAL FOOD PRODUCTS | BEACH GLEN | PA |
| National Forge & Ordnance | Irvine | PA |
| NATIONAL FORGE AND ORDNANCE CO. | IRVIN | PA |
| NATIONAL FORGE AND ORDNANCE CO. | IRVINE | PA |
| NATIONAL FORGE AND ORDNANCE COMPANY | IRVINE | PA |
| NATIONAL FORGE CO. | IRVINETON | PA |
| NATIONAL FORGE COMPANY | IRVINE | PA |
| NATIONAL GALVANIZING CO | PITTSBURGH | PA |
| NATIONAL GALVANIZING CO | PITTSBURHG | PA |
| NATIONAL GALVANIZING WORKS | MCKEESPORT | PA |
| NATIONAL GYPSUM CO. – BOILER HOUSE | NEW COLUMBIA | PA |
| NATIONAL GYPSUM COMPANY | MILTON | PA |
| National Heat & Power | Philadelphia | PA |
| NATIONAL LEAD AND OIL COMPANY | ALLEGHENY | PA |
| NATIONAL LEAD CO | PHILADELPHIA | PA |
| NATIONAL LEAD CO – BLDG #30 | PHILADELPHIA | PA |
| NATIONAL LEAD CO – BLDG #9 | PHILADELPHIA | PA |
| NATIONAL LEAD CO. | PITTSBURGH | PA |
| NATIONAL LEAD COMPANY – DUST ARRESTER & CONICAL HOPPER | PHILADELPHIA | PA |
| NATIONAL LEAD COMPANY, DUST ARRESTER & CONICAL HOPPER | PHILADELPHIA | PA |
| NATIONAL LEAD DOEHLER JARVIS CIV | POTTSTOWN | PA |
| NATIONAL MALLEABLE | Sharon | PA |
| NATIONAL MINING COMPANY | PITTSBURGH | PA |
| NATIONAL MINING COMPANY | SUGAR STATION | PA |
| NATIONAL MINING COMPANY | SYGAM | PA |
| NATIONAL MINING COMPANY | TRAVESKYN | PA |
| NATIONAL MOLASSES | PHILADELPHIA | PA |
| NATIONAL MOLLASES | PHILADELPHIA | PA |
| National Paper Company | Ransom | PA |
| National Plastics Company | Jeannette | PA |
| National Portland Cement | Bethlehem | PA |
| National Portland Cement Co | Bethlehem/Brodhead | PA |
| NATIONAL PORTLAND CEMENT COMPANY | HECKTOWN | PA |
| NATIONAL ROLL DIVISION | AVONMORE | PA |
| NATIONAL ROLLING MILL | MCKEESPORT | PA |
| National Standard | Mount Joy | PA |
| National Steel | Pittsburgh | PA |
| NATIONAL STEEL COMPANY | PITTSBURGH | PA |
| NATIONAL STEEL COMPANY | SHARON | PA |
| NATIONAL STEEL COMPANY | NEW CASTLE | PA |
| National Steel Service Center, Inc. | New Castle | PA |
| National Sugar | Philadelphia | PA |
| NATIONAL SUGAR REFINERY | PHILADELPHIA | PA |
| NATIONAL SUGAR REFINERY COMPANY | PHILADELPHIA | PA |
| NATIONAL SUGAR REFINING CO | PHILADELPHIA | PA |
| National Supply | Pittsburgh | PA |
| National Supply Co. | Etna | PA |
| National Supply Company | Ambridge | PA |
| National Tube | Ellwood City | PA |
| National Tube | Mckeesport | PA |
| National Tube | Pittsburgh | PA |
| National Tube Company | Pittsburgh | PA |
| NATIONAL TUBE COMPANY | MCKEESPORT | PA |
| NATIONAL TUBE COMPANY | PHILADELPHIA | PA |
| NATIONAL TUBE COMPANY | CHESTER | PA |
| NATIONAL TUBE COMPANY (a/k/a U.S. Steel) – Central Boiler House | McKeesport | PA |
| National Tube Company (Division National Works) | McKeesport | PA |
| NATIONAL TUBE COMPANY, MONONGAHELA FURNACES | MCKEESPORT | PA |
| NATIONAL TUBE COMPANY, PENNSYLVANIA DEPARTMENT | PITTSBURGH | PA |
| NATIONAL TUBE DIV | MCKEESPORT | PA |
| NATIONAL TUBE DIVISION – U.S. STEEL CORPORATION NATIONAL WORKS | MCKEESPORT | PA |
| National Tube Works | Mckeesport | PA |
| NATIONAL TUBE WORKS COMPANY | MCKEESPORT | PA |
| NATIONAL TUBE WORKS COMPANY | VERSAILLES | PA |
| National Valve | Lawrenceville | PA |
| NATIONAL VALVE | JOHNSTOWN | PA |
| NATIONAL VALVE & MANUFACT | PITTSBURGH | PA |
| NATIONAL VALVE AND MANUFACT | PITTSBURGH | PA |
| National Vulcanized Fiber | Kennett Square | PA |
| NATIONAL VULCANIZED FIBER COMPANY | YORKLYN | PA |
| National Vulcanized Fibre | Kennett Square | PA |
| NAVAL AVIATION SUPPLY DEPOT | PHILADELPHIA | PA |
| NAVAL BOILER AND TURBINE LABORATORY SCHOOL | PHILADELPHIA | PA |
| Naval Dry Dock | Philadelphia | PA |
| Naval Engineering Center | Philadelphia | PA |
| NAVAL ORDNANCE WORKS | MIDLAND | PA |
| NAVAL SHIP ENGINEERING CENTER | PHILADELPHIA | PA |
| NAVAL SUPPLY DEPOT | MECHANICSBURG | PA |
| NAVAL SUPPLY DEPOT – BLDG 2 | PHILADELPHIA | PA |
| Navy Regional Finance Center | Philadelphia | PA |
| Navy Yard Dry Dock | Philadelphia | PA |
| NAZARETH CEMENT CO | NAZARETH | PA |
| NAZARETH CEMENT COMPANY | NAZARETH | PA |
| Nazareth Hospital | Philadelphia | PA |
| NAZARETH PORTLAND CEMENT COMPANY | NAZARETH | PA |
| NAZARETH STEEL FABRICATORS | NAZARETH | PA |
| NCC PET FOOD CORP LADDIE | PHILADELPHIA | PA |
| NEALS WELDING AND FABRICAT | STEELTON | PA |
| NEALS WELDING AND FABRICATING | STEELTON | PA |
| NEATSFOOT OIL REFINERIES | PHILADELPHIA | PA |
| NELSON VALVE COMPANY | CHESTNUT HILL | PA |
| NELSON VALVE COMPANY | PHILADELPHIA | PA |
| NESBITT MANUFACTURING COMPANY | PHILADELPHIA | PA |
| Neshaminy High School | Langhorne | PA |
| NESHAMINY MALL – STRAWBRIDGE AND CLOTHIER DEPARTMENT STORE | BENSALEM | PA |
| Neshaminy Nursing | Doylestown | PA |
| NESQUE | HOMINY | PA |
| NEVILLE CHEMICAL CO – NEVILLE ISLAND | PITTSBURGH | PA |
| NEVILLE CHEMICAL CO – NEVILLE ISLAND – STORE ROOM | PITTSBURGH | PA |
| NEVILLE CHEMICAL COMPANY | PITTSBURGH | PA |
| NEVILLE CHEMICAL COMPANY | NEVILLE ISLAND | PA |
| NEVILLE CHEMICAL COMPANY – NEVILLE ISLAND PLANT | NEVILLE ISLAND | PA |
| NEVILLE CHEMICAL PLANT | PITTSBURGH | PA |
| NEVILLE COMPANY | NEVILLE ISLAND | PA |
| NEVILLE ISLAND | PITTSBURGH | PA |
| Neville Island Coke & Chemical | Neville Island | PA |
| Neville Island Coke & Chemical | Pittsburgh | PA |
| NEVILLE ST. APARTMENTS | PITTSBURGH | PA |
| NEW A AND B FOUNDRY INC | CONNELLSVILLE | PA |
| NEW AIR COND SYSTEM CLOSURE PLANT | LANCASTER | PA |
| NEW CASTLE AND LOWELL RAILWAY COMPANY | EDINBURG | PA |
| NEW CASTLE ELECTRIC COMPANY – ELECTRIC PLANT | NEW CASTLE | PA |
| New Castle Junior High School | New Castle | PA |
| NEW CASTLE LIGHT, HEAT, AND POWER COMPANY | NEW CASTLE | PA |
| NEW CASTLE PORTLAND CEMENT COMPANY | NEW CASTLE | PA |
| New Castle Refractories | New Castle | PA |
| NEW CASTLE SHOVEL COMPANY | NEW CASTLE | PA |
| NEW CASTLE STAMPING COMPANY | NEW CASTLE | PA |
| NEW CASTLE WATER COMPANY – WATER PLANT | NEW CASTLE | PA |
| New Cumberland Army Depot | New Cumberland | PA |
| NEW CUMBERLAND GENERAL DEPOT – ARMY AVIATION FAC., HANGER & SHOPS | NEW CUMBERLAND | PA |
| NEW DUQUESNE SCIENCE HALL | PITTSBURGH | PA |
| NEW FEDERAL BLDG | PITTSBURGH | PA |
| NEW FEDERAL OFFICE BUILDING | PHILADELPHIA | PA |
| NEW JERSEY AND PENNSYLVANIA TRACTION COMPANY | YARDLEY | PA |
| NEW JERSEY MILLS | PHILADELPHIA | PA |
| NEW JERSEY ZINC | PALMERTON | PA |
| NEW JERSEY ZINC CO | CENTER VALLEY | PA |
| NEW JERSEY ZINC CO | PALMERTON | PA |
| NEW JERSEY ZINC COMPANY | FRIEDENSVILLE | PA |
| NEW JERSEY ZINC COMPANY | FREEMANSBURG | PA |
| NEW JERSEY ZINC COMPANY | HAZARD | PA |
| NEW JERSEY ZINC COMPANY | SOUTH BETHLEHEM | PA |
| New Jersey Zinc Company – West Plant Slab Z | Palmerton | PA |
| NEW JERSEY ZINC COMPANY OF PENNSYLVANIA | EAST PLANT, PLAMERTON | PA |
| NEW JR HIGH SCHOOL | TROY | PA |
| NEW OFFICE BLDG. | LANCASTER | PA |
| NEW ORLEANS (USS) | PHILADELPHIA | PA |
| New Oxford Junior High School | New Oxford | PA |
| NEW PELLET PLANT | CORNWALL | PA |
| NEW RIVER AND POCAHONTAS CONSOLIDATED COAL COMPANY | PHILADELPHIA | PA |
| NEW SECONDARY SCHOOL | WYALUSING | PA |
| NEW SENIOR HIGH SCHOOL | QUARRYVILLE | PA |
| NEW SR. HIGH SCHOOL | LANCASTER | PA |
| NEW STEEL BUILDING, SPANG STEEL COMPANY | BUTLER | PA |
| New Williamsport High School | Williamsport | PA |
| New Wilmington City Hall & Courthouse | New Wilmington | PA |
| New York & Penna Co | Lock Haven | PA |
| New York & Pennsylvania Co. | Lock Haven | PA |
| NEW YORK & PENNSYLVANIA CO., INC. | JOHNSONBURG | PA |
| NEW YORK & PENNSYLVANIA CO., INC. | LOCK HAVEN | PA |
| NEW YORK & PENNSYLVANIA CO., INC. – CASTANEA MILL | LOCK HAVEN | PA |
| NEW YORK & PENNSYLVANIA CO., INC. – CHEMICAL PILOT PLANT | LOCK HAVEN | PA |
| NEW YORK & PENNSYLVANIA CO., INC. – LOCK HAVEN MILL | LOCK HAVEN | PA |
| NEW YORK & PENNSYLVANIA CO., INC. – SEMICHEMICAL PILOT PLANT | LOCK HAVEN | PA |
| NEW YORK & PENNSYLVANIA PAPER CO – BOILER ROOM | HAVEN | PA |
| NEW YORK & PENNSYLVANIA PAPER CO – BOILER ROOM | LOCK HAVEN | PA |
| NEW YORK AND PENNSYLVANIA COMPANY | JOHNSONBURG | PA |
| NEW YORK PHILADELPHIA AND NORFOLK RAILWAY COMPANY | PHILADELPHIA | PA |
| NEW YORK SHIPBUILDING COMPANY | PHILADELPHIA | PA |
| NEW YORK STATE NATURAL GAS – LEIDY STATION | RENOVO | PA |
| NEW YORK STATE NATURAL GAS – OAKFORD COMPRESSOR STATION | DELMONT | PA |
| NEW YORK STATE NATURAL GAS – SABINSVILLE COMPRESSOR STATION | SABINSVILLE | PA |
| NEW YORK STATE NATURAL GAS – TONKIN STATION | MURRAYSVILLE | PA |
| New York State Natural Gas Company | Delmont | PA |
| NEW YORK STATE NATURAL GAS CORPORATION – COMPRESSOR STATION | SABINSVILLE | PA |
| NEW YORK STATE NATURAL GAS, 86 PUMP STATION LANE | LAWRENCEVILLE | PA |
| NEW YORK WILKINS COMPANY ENGINEERS | PITTSBURGH | PA |
| NEW YORK WIRE CLOTH COMPANY | YORK | PA |
| NEWARK PROCESSING CO | CHESTER | PA |
| NEWBURN GLASS COMPANY | ROYERSFORD | PA |
| NEWCOR | MUELLER | PA |
| NEWMAN & CO INC | PHILADELPHIA | PA |
| NEWPORT (USS) | PHILADELPHIA | PA |
| NEWTON COAL MINING COMPANY | PITTSTON | PA |
| NICE BALL BEARING | KULPAVILLE | PA |
| NICE BALL BEARING | KULPSVILLE | PA |
| NICE BALL BEARING CO | PHILADELPHIA | PA |
| NICETOWN | PHILADELPHIA | PA |
| NICETOWN PLATE WASHER COMPANY | NICETOWN, PHILADELPHIA | PA |
| NICHOLSON FILE COMPANY | PHILADELPHIA | PA |
| NICHOLSON FILE COMPANY – RED LION & DECATUR ROADS | PHILADELPHIA | PA |
| NICHOLSON FILE COMPANY, RED LION & DECATUR RDS. | PHILADELPHIA | PA |
| Nickel Plumbing & Heating | Pittsburgh | PA |
| Nicolet Industries | Ambler | PA |
| Nicolet Industries | Norristown | PA |
| Nicolet Industries | Lansdale | PA |
| NICOLETTE INDUSTRIES | AMBLER | PA |
| NILES BUILDING | PHILADELPHIA | PA |
| NILES-BEMENT-POND COMPANY | PHILADELPHIA | PA |
| NILES-BEMENT-POND COMPANY | NICETOWN | PA |
| NIXON THEATRE | PITTSBURGH | PA |
| NM. PENN COLLIERY | SHAFT | PA |
| NO 2 SHAFT | WILLIAMSTOWN | PA |
| NO AM REFR | CURWENSVILLE | PA |
| NOAH BARLOW | PHILADELPHIA | PA |
| Norfolk & Western Railway | Erie | PA |
| NORFOLK SOUTHERN CORPORATION | HOLLIDAYSBURG | PA |
| NORFOLK WESTERN RAILROAD | ERIE | PA |
| NORFOLK WESTERN SHOPS | NOT PROVIDED | PA |
| NORLAND SHIPPING & TRADING CO | MORRISVILLE | PA |
| NORRIS SMELTING & REFINING | SWEDELAND | PA |
| Norristown Hospital | Norristown | PA |
| NORRISTOWN MAGNESIA AND ASBESTOS COMPANY | NORRISTOWN | PA |
| Norristown Municipal Sanitation Department | Norristown | PA |
| NORRISTOWN POST OFFICE | NORRISTOWN | PA |
| Norristown State Hospital | Norristown | PA |
| NORTH AMERICAN LACE COMPANY | PHILADELPHIA | PA |
| NORTH AMERICAN REFR CO | WOMELSDORF | PA |
| NORTH AMERICAN REFRACT CO | PITTSBURGH | PA |
| North American Refractories | Womelsdorf | PA |
| North American Refractory | Curwensville | PA |
| NORTH AMERICAN ROCKWELL | READING | PA |
| NORTH AMERICAN ROCKWELL CORP. | NEW CASTLE | PA |
| NORTH BRANCH STEEL COMPANY | DANVILLE | PA |
| NORTH BROTHERS COMPANY | COATESVILLE | PA |
| NORTH BROTHERS MANUFACTURING COMPANY | PHILADELPHIA | PA |
| NORTH CAMBRIA RAILWAY COMPANY | PITTSBURGH | PA |
| NORTH CAMBRIA RAILWAY COMPANY | PATTON | PA |
| North Cornwall Furnace | Cornwall | PA |
| NORTH CORNWALL FURNACE COMPANY | CORNWALL | PA |
| North Cumberland Company | Riverside | PA |
| NORTH HUNTINGTON TWP HIGH SCHOOL | IRWIN | PA |
| NORTH PIPE SHOP – STATION 270 | ALIQUIPPA | PA |
| NORTH RESERVE BASIN | PHILADELPHIA | PA |
| NORTH SEWICKLEY TOWNSHIP | BEAVER COUNTY | PA |
| NORTH SIDE OF INDUSTRIAL HIGHWAY | EDDYSTONE | PA |
| NORTH SIDE PACKING COMPANY | PITTSBURGH | PA |
| NORTHAMPTON TRACTION COMPANY | EASTON | PA |
| NORTHEAST HIGH SCHOOL – COTTMAN AVENUE | PHILADELPHIA | PA |
| Northeast Water Pollution Control Plant | PHILADELPHIA | PA |
| NORTHERN LIGHT (T-AK-284) | CHESTER | PA |
| NORTHERN METALS COMPANY | TACONY | PA |
| Northern Ore Co. | Easton | PA |
| Northside Cooperage Company | Pittsburgh | PA |
| NORTHVIEW HEIGHTS ELEMENTARY SCHOOL | PITTSBURGH | PA |
| NORTHVIEW HOUSING, HAZLET AND SPRING HILL | PITTSBURGH | PA |
| NORTHWEST COLLERY | CARBONDALE | PA |
| NORTHWESTERN MINING AND EXCHANGE COMPANY | HELLEN MILLS | PA |
| NORTHWESTERN PENNSYLVANIA RAILWAY COMPANY | MEADVILLE | PA |
| NOSCO | ERIE | PA |
| NOTTINGHAM COLLIERY | PLYMOUTH | PA |
| NOVINGERS, INCORPORATED | HARRISBURG | PA |
| NUCLEAR MAT & EQUIP CORP | APOLLO | PA |
| NUCLEAR MATERIALS & EQUIPMENT | APOLLO | PA |
| Nuclear Materials and Equipment Company – Apollo Plant | Apollo | PA |
| NUCLEAR MATERIALS AND EQUIPMENT CORPORATION (NUMEC) – NUCLEAR PLANT | APOLLO | PA |
| NUMBER 1 NUMBER 4 BLAST FURNACE | JOHNSTOWN | PA |
| NUMBER 10 BREAKER | PITTSTON | PA |
| NUMBER 2 SHAFT COLLIERY | KINGSTON | PA |
| NUMBER 3 BOILDER HOUSE | NICETOWN, PHILADELPHIA | PA |
| NUMBER 3 ROLLILNG MILL | JOHNSTOWN | PA |
| NUMBER 4 BREAKER | KINGSTON | PA |
| NUMBER 4 COLLIERY | KINGSTON | PA |
| NUMBER 4 ROLLING MILL | JOHNSTOWN | PA |
| NUMBER 5 AND NUMBER 6 BLAST FURNACE | JOHNSTOWN | PA |
| NUMBER 6 BOLLIERY | PITTSTON | PA |
| NUMBER 6 COLLIERY | INKERMAN | PA |
| NUMBER 6 COLLIERY | PITTSTON | PA |
| NUMBER 8 BOLLIERY | PITTSTON | PA |
| NUMBER 8 GRUTIER MILL | JOHNSTOWN | PA |
| NUMBER 9 BREAKER | PITTSTON | PA |
| NUMBER 9 COLLIER | PETTSTON | PA |
| NUMBER 9 COLLIERY NEAR | PITTSTON | PA |
| NUTRITION PRODUCTS | PHILADELPHIA | PA |
| NUTTAL WORKS | PITTSBURGH | PA |
| NY & PA Co. | Johnsonburg | PA |
| O AMOS CO DIV MCDONOUGH C | PHILADELPHIA | PA |
| O C Cluss Lumber Co | Uniontown | PA |
| O HORA JOHN F & SONS | SCRANTON | PA |
| O HORA JOHN F AND SONS | SCRANTON | PA |
| O. HOMMEL CO. | CARNEGIE | PA |
| O.F. ZURN | PHILADELPHIA | PA |
| Oak Summit Apartments | Philadelphia | PA |
| O’BRIEN MACHINERY COMPANY | PHILADELPHIA | PA |
| O’BRIEN RUBBER THREAD AND WEBBING COMPANY | CATASAUQUA | PA |
| OCCIDENTAL CHEMICAL | POTTSTOWN | PA |
| OCEAN COAL COMPANY | HERMINIE | PA |
| OCEAN COAL COMPANY | PHILADELPHIA | PA |
| OF AMERICA PARK WORKERS | PITTSBURGH | PA |
| OFFICE & WHSE. R. C. A. | LANCASTER | PA |
| OFFICE BUILDING – 1500 WALNUT STREET | PHILADELPHIA | PA |
| OHIO AND PITTSBURGH MILK COMPANY | PITTSBURGH | PA |
| OHIO PENNSYLVANIA SYSTEM | NEW CASTLE | PA |
| OHIO SEVICE COMPANY | NEW PHILADELPHIA | PA |
| OHIO SPRING SPECIALTIES | LEECHBURG | PA |
| Oil City Glass Co Division Natl Can | Oil City | PA |
| Oil City Glass Company | Oil City | PA |
| OIL HEAT SERVICE | MIDDLEBURG | PA |
| OIL WELL SUPPLY CO | OIL CITY | PA |
| Oilwell Div Us Steel | Oil City | PA |
| OKINAWA (USS) | PHILADELPHIA | PA |
| Oklahoma Gas & Electric | Ponca City | PA |
| Okonite Co. (Hazard Wire Rope) | Wilkes Barrre | PA |
| OLD FORGE BREAKER | DUNMON | PA |
| OLD FORGE COLLIERIES | NEW AVOCA | PA |
| OLD FORGE COLLIERIES | SCRANTON | PA |
| OLD FOURTH WARD SCHOOL | PITTSBURGH | PA |
| OLD MEADOW WORKS | PITTSBURGH | PA |
| Oldman Boiler Works | Erie | PA |
| OLIN MATHIESON CHEMICAL | LAKE CHARLES | PA |
| OLIN MATHIESON CHEMICAL CORP. | MCKEES ROCKS | PA |
| OLIN PLANT | FOGELSVILLE | PA |
| OLIVER AND ROBERTS WIRE COMPANY | PITTSBURGH | PA |
| OLIVER AND SNYDER STEEL COMPANY | OLIVER | PA |
| OLIVER AND SNYDER STEEL COMPANY | PITTSBURGH | PA |
| OLIVER AND SNYDER STEEL COMPANY | ALLEGHENY | PA |
| OLIVER BUILDING | PITTSBURGH | PA |
| Oliver Iron & Steel Co. | Pittsburg | PA |
| OLIVER IRON AND STEEL COMPANY | PITTSBURGH | PA |
| OLIVER IRON MINING COMPANY | PITTSBURGH | PA |
| OLIVER IRON STEEL COMPANY | PITTSBURGH | PA |
| OLIVER NACE GREENHOUSE | PERKASIE | PA |
| OLIVER SNYDER STEEL COMPANY | OLIVER | PA |
| OLIVER WIRE COMPANY, LIMITED | PITTSBURGH | PA |
| Olmstead Air Force Base | Middletown | PA |
| OLNEY ANNEX HIGH SCHOOL – WYOMING AVENUE | PHILADELPHIA | PA |
| OLNEY HIGH SCHOOL – FRONT & DUNCANNON STREETS | PHILADELPHIA | PA |
| Olsen Industries Inc | Carengie | PA |
| OLSON ENGINEERING | PITTSBURGH | PA |
| OLSON ENGINEERING CO | PITTSBURGH | PA |
| OLYPHANT COLLIERY | OLYPHANT | PA |
| OLYPHANT POWER PLANT | OLYPHANT | PA |
| OMAHA AND COUNCIL BLUFFS RAILWAY AND BRIDGE COMPANY | COUNCIL BLUFFS | PA |
| ONDERDONK HEATING AND VENTILATING COMPANY | PHILADELPHIA | PA |
| ONE OLIVER PLAZA BUILDING | PITTSBURGH | PA |
| ONEIDA COLLIERY | ONEIDA | PA |
| ONEIDA MINING | HOMER CITY | PA |
| Oneida Mining Company | Armagh – Bush Valley | PA |
| Onex Inc | Erie | PA |
| ONOPONCA CITY | CHESTER | PA |
| ONYX | ERIE | PA |
| OPEN HEARTH DIVISION | HOMESTEAD | PA |
| ORIENT COAL AND COKE COMPANY | NEW SALEM | PA |
| ORIENT COAL AND COKE COMPANY | UNIONTOWN | PA |
| ORIENT COKE COMPANY | UNIONTOWN | PA |
| ORIENT COKE COMPANY | ORIENT | PA |
| ORINOKA MILLS | PHILADELPHIA | PA |
| ORION POWER HOLDINGS INCORPORATED | ELRAMA | PA |
| ORION POWER HOLDINGS INCORPORATED | NEW CASTLE | PA |
| ORION POWER MIDWEST, LLC | ELRAMA | PA |
| ORION POWER MIDWEST, LLC | WEST PITTSBURGH | PA |
| ORR & SEMBOWER INC | READING | PA |
| ORR AND SEMBOWER INC | MIDDLETOWN | PA |
| Orr Sembauer Co | Middletown | PA |
| ORRTANNA CANNING COMPANY | ORRTANNA | PA |
| OSBORN MACHINE CO. | DUBOIS | PA |
| OSCAR MEYER MEATS | PHILADELPHIA | PA |
| Oswald & Hess Company, Inc – 1314 Spring Garden Ave. | Pittsburgh | PA |
| Otis Steel Co. | Pittsburg | PA |
| Otto Milk Company | Pittsburgh | PA |
| OUR LADY OF MERCY SCHOOL | MONROEVILLE | PA |
| OUR LADY OF MT CARMEL CONVENT | CARBONDALE | PA |
| OVERBROOK STEAM HEAT COMPANY – OVERBROOK HEATING PLANT | PHILADELPHIA | PA |
| OVERBROOK STEAM HEAT COMPANY – POWER PLANT | PHILADELPHIA | PA |
| OVERBROOK STEAM HEAT COMPANY – WOODBINE AVENUE & UPLANT WAY | PHILADELPHIA | PA |
| OVERBROOK STEAM HEAT COMPANY, WOODBINE AVE. & UPLANT WAY | PHILADELPHIA | PA |
| Owens Corning Fiberglas | Ephrata | PA |
| Owens Corning Fiberglas Corp | Berwyn | PA |
| Owens Corning Fiberglas Corp | Philadelphia | PA |
| OWENS CORNING FIBERGLASS | BERWICK | PA |
| OWENS CORNING FIBERGLASS | BERWYN | PA |
| Owens Corning Fiberglass Corp. | Berwyn | PA |
| OWENS ILLINOIS | CLAXTON | PA |
| OWENS ILLINOIS | CLARION | PA |
| OWENS ILLINOIS | BARDSTOWN | PA |
| OWENS ILLINOIS GLASS COMPANY – GLASS CONTAINER DIVISION | CLARION | PA |
| OWENS-CORNING FIBERGLAS | BERWYN | PA |
| OWENS-CORNING FIBERGLAS | PHILADELPHIA | PA |
| OWENS-CORNING FIBERGLAS CORP. | BERWYN | PA |
| OWENS-CORNING FIBERGLAS CORP. | PHILADELPHIA | PA |
| Owens-Illinois | Brookville | PA |
| OWENS-ILLINOIS GLASS CO | PITTSTON | PA |
| OXFORD CABINET CO | OXFORD | PA |
| Oxychem | Berwyn | PA |
| OXY-LOY | ALLENTOWN | PA |
| OZENDA SMOKELESS COAL COMPANY | BOSWELL | PA |
| P & L | MCKEES ROCKS | PA |
| P & Le Railroad | Beaver Falls | PA |
| P H GLADFELTER CO – SPRING GROVE | YORK | PA |
| P H GLATFELTER COMPANY | SPRING GROVE | PA |
| P P & L OFFICE BLDG | KINGSTON | PA |
| P P G INDUSTRIES INC | SPRINGDALE | PA |
| P P G INDUSTRIES INC | MEADVILLE | PA |
| P&LE Railroad | McKees Rock | PA |
| P. H. GLATFELTER CO – GLADFELTER BUILDING | SPRING GROVE | PA |
| P. H. GLATFELTER COMPANY | SPRING GROVE | PA |
| P. MCGRAW AND WOOL COMPANY | ALLEGHENY | PA |
| P. MCGRAW WOOL COMPANY | PITTSBURGH | PA |
| P.A. & S. SMALL | YORK | PA |
| P.A. Power & Light – Sunbury Station | Sunbury | PA |
| P.F. MAGIN AND COMPANY, JONES AND LAUGHLIN BUILDING | PITTSBURGH | PA |
| P.H. BERMAN & SONS | PHILADELPHIA | PA |
| P.H. GLATFELDER COMPANY | SPRING GROVE | PA |
| P.H. Glatfelter | Spring Grove | PA |
| P.J. RITTER COMPANY | PHILADELPHIA | PA |
| P.O. #13014-S-601 FLOOR PLANT | LANCASTER | PA |
| PA FORGE DIV OF CHERTRON CORP | PHILADELPHIA | PA |
| PA MALL IRON CORP | LANCASTER | PA |
| PABST BREWING COMPANY | FOGELSVILLE | PA |
| PACIFIC RAILROAD WESTERN LINES | CONWAY | PA |
| Packard Building – Office | Philadelphia | PA |
| PACKER COLLIERY #4 | LOST CREEK | PA |
| PACKER COLLIERY #5 | LOST CREEK | PA |
| Pacor | Chester | PA |
| Pacor Inc | Philadelphia | PA |
| Page Steel & Wire Co. | Monessen | PA |
| PAGE WOVEN WIRE FENCE COMPANY | MONESSEN | PA |
| PAGE WOVEN WIRE FENCE COMPANY | MORESSEN | PA |
| PALLADINON | POTTSTOWN | PA |
| PALMERTON ELEMENTARY | PALMERTON | PA |
| PALMERWELD FABRICATING COMPANY | AMBLER | PA |
| Pangborn Corporation | Bethlehem | PA |
| Pangborn Corporation | Homestead | PA |
| PAOLI ELEMENTARY | PAOLI | PA |
| PAPER MANUFACTURERS | PHILADELPHIA | PA |
| PAPER MFG CO | PHILADELPHIA | PA |
| Papercraft Plant | Pittsburgh | PA |
| Parade Lumber Co | Erie | PA |
| Paragon Packaging Prod Inc | Girard | PA |
| PARISH DIV. DANA | READING | PA |
| Parish Pressed Steel (Dana Corp.) | Reading | PA |
| PARK AND TILFORD DISTILLERY COMPANY | BROWNSVILLE | PA |
| Park City Mall | Lancaster | PA |
| PARK CITY MALL – GIMBELS DEPARTMENT STORE | LANCASTER | PA |
| PARK CITY SHOPPING CENTER | PARK CITY | PA |
| PARK CITY SHOPPING CENTER | LANCASTER | PA |
| PARK CITY SHOPS – ROUTET 30 BYPASS | LANCASTER | PA |
| PARK CITY STORES | PARK CITY | PA |
| PARK HOTEL | WILLIAMSPORT | PA |
| PARK SHOPS | MANTUA | PA |
| PARK STEEL COMPANY | PITTSBURGH | PA |
| PARK STEEL WORKS | PITTSBURGH | PA |
| PARK WORKS | PITTSBURGH | PA |
| PARKERSBURG IRON AND STEEL COMPANY | PITTSBURGH | PA |
| PARKESBURG IRON COMPANY | PARKESBURG | PA |
| PARKVALE SAVINGS AND LOAN – FORBES AVENUE | OAKLAND | PA |
| PARKVIEW COURT APARTMENTS | YEADON | PA |
| PARKVIEW COURT APARTMENTS BUILDING B | YEADON | PA |
| PARKVIEW COURT APARTMENTS BUILDING T | YEADON | PA |
| PARKVIEW COURT APARTMENTS BUILDING Z 2 | YEADON | PA |
| Parkway Apartment | Harrisburg | PA |
| PARKWAY MANOR ELEM SCHOOL | LEHIGH COUNTY | PA |
| Parsons Insulation | Wilkes Barre | PA |
| PARVIEW COURT APARTMENTS | YEADON | PA |
| PASCAGOULA STREET RAILWAY AND POWER COMPANY | SCRANTON | PA |
| PASSAVANT HOSPITAL | PITTSBURGH | PA |
| PATERSON PARCHMENT PAPER COMPANY | BRISTOL | PA |
| PATERSON PARCHMENT PAPER COMPANY | EDGLEY | PA |
| PAUL AND BEEKMAN CO | PHILADELPHIA | PA |
| PAUL B. HENDEL & COMPANY | READING | PA |
| PAUL BRONZE & BRASS CORP | EDDINGTON | PA |
| Paul E. Stare Plumbing & Heating | Mechanicsburg | PA |
| Paul Lumber And Supply Co | Pittsburgh | PA |
| Paul W. Anderson | Stroudsburg | PA |
| PAULSON ABBOT INC | CROYDON | PA |
| PAWHATTAN COAL AND COKE COMPANY | SYKESVILLE | PA |
| PAXTANG ELECTRIC COMPANY – POWER PLANT | HARRISBURG | PA |
| PAXTON IRON AND STEEL COMPANY | HARRISBURG | PA |
| PAXTRON FURNACES | HARRISBURG | PA |
| PEABODY VERTICAL AIR HEATER | NEWELL | PA |
| Peach Bottom III | Delta | PA |
| PEACH BOTTOM NUCLEAR GENERATING STATION – UNIT 1 | DELTA | PA |
| PEACH BOTTOM NUCLEAR GENERATING STATION – UNIT 2 | DELTA | PA |
| PEACH BOTTOM NUCLEAR GENERATING STATION – UNIT 3 | DELTA | PA |
| Peach Bottom Nuclear Plant | York County | PA |
| Peachbottom Nuclear Plant – Unit 2 | Delta | PA |
| Peachbottom Powerhouse | DELTA | PA |
| Peachbottom Reactor II | Delta | PA |
| PEARSON MFG CO INC | PITTSBURGH | PA |
| Pebbco Industries | Lancaster | PA |
| Peckerman Company | Philadelphia | PA |
| PECO | Philadelphia | PA |
| PECO – CROMBY POWER PLANT | PHOENIXVILLE | PA |
| Peco Barbados Island Powerhouse | Norristown | PA |
| PECO Croydon Powerhouse | Croydon | PA |
| Peco Delaware Station Powerhouse | Philadelphia | PA |
| Peco Eddystone Station Powerhouse | Eddystone | PA |
| PECO Energy – West Conshohocken Gas Plant | WEST CONSHOHOKEN | PA |
| PECO ENERGY COMPANY | PHILADELPHIA | PA |
| PECO, Cromby Station | Phoenixville | PA |
| PECO-Cromby Station | Norristown | PA |
| Peco-Philadelphia Electric | Philadelphia | PA |
| Pecora Inc. | Philadelphia | PA |
| PEERLESS DYE CO | PHILADELPHIA | PA |
| PEERLESS DYEING | PHILADELPHIA | PA |
| PENCOYD IRON WORKS | PENCOYD | PA |
| PENCOYD IRON WORKS | PHILADELPHIA | PA |
| Penelec Power Plant | Shawville | PA |
| Penhurst State Institute | Spring City | PA |
| PENN ALUMINUM | ERIE | PA |
| PENN ARGYL HIGH SCHOOL | PEN ARGYL | PA |
| PENN BRADFORD COMPANY | PHILADELPHIA | PA |
| Penn Center | Philadelphia | PA |
| PENN CENTER TWO | PHILADELPHIA | PA |
| PENN CENTRAL | ENOLA | PA |
| PENN CENTRAL | ALTOONA | PA |
| PENN CENTRAL | HOLIDAYSBURG | PA |
| PENN CENTRAL | SOUTH ALTOONA | PA |
| PENN CENTRAL LIGHT AND POWER COMPANY | SAXTON | PA |
| PENN CENTRAL LIGHT AND POWER COMPANY | ALTOONA | PA |
| PENN CENTRAL RAIL ROAD COMPANY | PHILADELPHIA | PA |
| PENN CENTRAL RAILROAD CO | PHILADELPHIA | PA |
| Penn Dairies | Lancaster | PA |
| Penn Dairies | Pottsville | PA |
| PENN DAIRIES, GREENFIELD RD. | LANCASTER | PA |
| PENN DAIRIES, INCORPORATED | YORK | PA |
| PENN DIXIE CEMENT COMPANY | NAZARETH | PA |
| PENN DIXIE CEMENT CORP – PLANT NO 9 | WEST WINFIELD | PA |
| PENN ELECTRIC | JOHNSTOWN | PA |
| PENN ELECTRIC | WARREN | PA |
| Penn Electric Co | Shawville | PA |
| PENN FISHING | PHILADELPHIA | PA |
| Penn Fruit Co. – Warehouse | Philadelphia | PA |
| Penn Fruit Company | Philadelphia | PA |
| PENN GAS COAL COMPANY – COAL PLANT | IRWIN | PA |
| PENN HARDWARE COMPANY | READING | PA |
| PENN HEAT AND POWER COMPANY | WILKENSBURG | PA |
| PENN HEAT AND POWER COMPANY | WILKINSBURG | PA |
| PENN HIGH SCHOOL | KINGSTON | PA |
| Penn Jersey Boiler Company | Pennsauken | PA |
| PENN JERSEY TRANSMISSION CORP. | BECHTELSVILLE | PA |
| PENN JERSEY TRANSMISSION CORP. | BOYERTOWN | PA |
| PENN JERSEY TRANSMISSION CORP. | GRANTVILLE | PA |
| PENN JERSEY TRANSMISSION CORP. | LILLY | PA |
| PENN JERSEY TRANSMISSION CORP. | PERULACK | PA |
| PENN MALL IRON | LANDISVILLE | PA |
| PENN MO FIRE BRICK CO | HARRISBURG | PA |
| Penn Mo Firebrick Co | Harrisburg | PA |
| PENN MO FIREBRICK CO | PITTSBURGH | PA |
| Penn Optical | Reading | PA |
| PENN POWER | NEW EAGLE | PA |
| PENN POWER & LIGHT – MONTOUR STATION | WASHINGTONVILLE | PA |
| PENN POWER COMPANY | NEW CASTLE | PA |
| PENN POWER COMPANY | WEST PITTSBURGH | PA |
| PENN PUBLIC SERVICE COMPANY | PHILIPSBURG | PA |
| PENN PUBLIC SERVICE COMPANY | JOHNSTOWN | PA |
| PENN PUBLIC SERVICE CORPORATION | JOHNSTOWN | PA |
| PENN PUBLIC SERVICE CORPORATION | SEWARD | PA |
| PENN RANGE COMPANY | PHILADELPHIA | PA |
| PENN RILTON COMPANY | WEST ELIZABETH | PA |
| PENN SHERATON HOTEL | PHILADELPHIA | PA |
| PENN SHOVEL COMPANY | CORRY | PA |
| PENN STATE EDUCATIONAL ASSOCIATION BUILDING | HARRISBURG | PA |
| Penn State University | State College | PA |
| Penn State University | University Park | PA |
| PENN STEEL COMPANY | PHILADELPHIA | PA |
| PENN STEEL COMPANY | STEELTON | PA |
| PENN TECH | JOHNSONBURG | PA |
| PENN TREATY AMERICAN CORPORATION | PHILADELPHIA | PA |
| PENN TREATY OVERALL | PHILADELPHIA | PA |
| PENN VENTILATOR CO | PHILADELPHIA | PA |
| PENN VENTILATOR COMPANY | PHILADELPHIA | PA |
| PENN-ALLEN CEMENT COMPANY | NEAR NAZARETH | PA |
| PENN-ALLEN PORTLAND CEMENT COMPANY | BATH | PA |
| PENN-ALLEN PORTLAND CEMENT COMPANY | ALLENTOWN | PA |
| PENN-BRADFORD APPL. | PHILADELPHIA | PA |
| Pennco Industries | Warren | PA |
| PENN-DIXIE CEMENT COMPANY | WEST WINFIELD | PA |
| PENNHURST ST SCHOOL | SPRING CITY | PA |
| Penns Valley Insulation | Lester | PA |
| Penns Valley Insulation Company | Lester | PA |
| PENNSALT CHEMICAL CO – PENNSYLVANIA SALT MFG. CO. – WYNDMOOR | PHILADELPHIA | PA |
| PENNSALT CHEMICAL CO – WYNDMOOR | PHILADELPHIA | PA |
| PENNSALT CHEMICALS CORPORATION | KING OF PRUSSIA | PA |
| PENNSBURY POTTERY CO | HARRISVILLE | PA |
| PENNSBURY POTTERY CO | MORRISVILLE | PA |
| PENNSYLAVANIA COAL COMPANY | PITTSTON | PA |
| PENNSYLVANIA RAILROAD | READING | PA |
| PENNSYLVANIA ACADEMY OF FINE ARTS – BROAD STREET | PHILADELPHIA | PA |
| Pennsylvania Academy of the Fine Arts | Philadelphia | PA |
| PENNSYLVANIA BOLT AND NUT COMPANY | LEBANON | PA |
| PENNSYLVANIA BRAKE BEAM COMPANY | DANVILLE | PA |
| PENNSYLVANIA CEMENT COMPANY | BATH | PA |
| Pennsylvania Central Power & Transit | Williamsburg | PA |
| PENNSYLVANIA CENTRAL RAILROAD, 30TH ST. STATION | PHILADELPHIA | PA |
| PENNSYLVANIA CHOCOLATE COMPANY | PITTSBURGH | PA |
| PENNSYLVANIA COAL AND COKE COMPANY | EHRENFELD | PA |
| PENNSYLVANIA COAL COMPANY | AVOCA | PA |
| PENNSYLVANIA COAL COMPANY | DUNAMERE | PA |
| PENNSYLVANIA COAL COMPANY | DUNMON | PA |
| PENNSYLVANIA COAL COMPANY | DUNNON | PA |
| PENNSYLVANIA COAL COMPANY | MT. LOOKOUT | PA |
| PENNSYLVANIA COAL COMPANY | SEBASTOPOL | PA |
| PENNSYLVANIA COAL COMPANY | PITTSTON | PA |
| PENNSYLVANIA COAL COMPANY | SCRANTON | PA |
| PENNSYLVANIA COAL COMPANY | DUNMORE | PA |
| PENNSYLVANIA COAL COMPANY | PLAINS JUNCTION | PA |
| PENNSYLVANIA COAL COMPANY | WYOMING | PA |
| PENNSYLVANIA COAL COMPANY OLD FORGE BREAKER | DUNMORE | PA |
| PENNSYLVANIA COAL COMPANY, #8 WASHERY | PITTSTON | PA |
| PENNSYLVANIA COAL COMPANY, EWEN BREAKER | PITTSTON | PA |
| Pennsylvania Cola Co. | Dunmore | PA |
| PENNSYLVANIA COMPANY | PITTSBURGH | PA |
| PENNSYLVANIA COMPANY | CONWAY | PA |
| PENNSYLVANIA COMPANY, LINES WEST OF PITTSBUGH | ALLEGHENY | PA |
| Pennsylvania Edison Co | Williamsburg | PA |
| PENNSYLVANIA ELECTRIC | SAXTON | PA |
| PENNSYLVANIA ELECTRIC | NEW FLORENCE | PA |
| Pennsylvania Electric – Keystone Generating Station | Plumcreek | PA |
| Pennsylvania Electric Co | Erie | PA |
| Pennsylvania Electric Co | Seward | PA |
| Pennsylvania Electric Co Erie Plant | Erie | PA |
| Pennsylvania Electric Co Steam Heat Dept Front St Station | Erie | PA |
| PENNSYLVANIA ELECTRIC CO. | HOMER CITY | PA |
| PENNSYLVANIA ELECTRIC CO. – CONEMAUGH | NEW FLORENCE | PA |
| PENNSYLVANIA ELECTRIC CO. – FRONT ST. POWER STATION | ERIE | PA |
| PENNSYLVANIA ELECTRIC CO. – FRONT STREET STATION | ERIE | PA |
| PENNSYLVANIA ELECTRIC CO. – HOMER CITY GENERATING STATION | HOMER CITY | PA |
| PENNSYLVANIA ELECTRIC CO. – SHAWVILLE GENERATING STATION | SHAWVILLE | PA |
| PENNSYLVANIA ELECTRIC CO. – SHAWVILLE GENERATING STATION – UNIT 4 | SHAWVILLE | PA |
| PENNSYLVANIA ELECTRIC CO. – SHAWVILLE GENERATING STATION – UNITS 3 & 4 | SHAWVILLE | PA |
| Pennsylvania Electric Co.- Seward Generating Station | Seward | PA |
| Pennsylvania Electric Company | Altoona | PA |
| Pennsylvania Electric Company | Williamsburg | PA |
| Pennsylvania Electric Company | Homer City | PA |
| PENNSYLVANIA ELECTRIC COMPANY – CONEMAUGH GENERATING STATION | New Florence | PA |
| Pennsylvania Electric Company – Conemaugh Generating Station – Unit 1 | New Florence | PA |
| PENNSYLVANIA ELECTRIC COMPANY – CONEMAUGH GENERATING STATION – Unit 2 | New Florence | PA |
| PENNSYLVANIA ELECTRIC COMPANY – CONEMAUGH GENERATING STATION – Units 1 & 2 | New Florence | PA |
| Pennsylvania Electric Company – Conemaugh Station | New Florence | PA |
| PENNSYLVANIA ELECTRIC COMPANY – FRONT ST STATION | ERIE | PA |
| Pennsylvania Electric Company – Homer City Generating Station | HOMER CITY | PA |
| Pennsylvania Electric Company – Keystone Generating Station | Shelocta | PA |
| PENNSYLVANIA ELECTRIC COMPANY – SEWARD | SEWARD | PA |
| PENNSYLVANIA ELECTRIC COMPANY – SEWARD GENERATING STATION | Seward | PA |
| PENNSYLVANIA ELECTRIC COMPANY – SEWARD STATION – WESTMORELAND COUNTY | SEWARD | PA |
| PENNSYLVANIA ELECTRIC COMPANY – SHAWVILLE PLANT | SHAWVILLE | PA |
| PENNSYLVANIA ELECTRIC COMPANY – SHAWVILLE PLANT – UNIT 3 | SHAWVILLE | PA |
| PENNSYLVANIA ELECTRIC COMPANY – SHAWVILLE PLANT – UNITS 3 AND 4 | SHAWVILLE | PA |
| Pennsylvania Electric Company – Shawville Station | Shawville | PA |
| PENNSYLVANIA ELECTRIC COMPANY – SHAWVILLE STATION – UNITS #3 & #4 | SHAWVILLE | PA |
| Pennsylvania Fruit | Philadelphia | PA |
| PENNSYLVANIA FURNACE COMPANY | SHERIDAN | PA |
| Pennsylvania Gas Company | Erie | PA |
| Pennsylvania Gas Company | Roystone | PA |
| Pennsylvania Gas Company | Sheffield | PA |
| PENNSYLVANIA GENERAL IMP. COMPANY | PHILADELPHIA | PA |
| PENNSYLVANIA GENERAL IMP. COMPANY | ROCKLEDGE | PA |
| PENNSYLVANIA HARDWARE COMPANY | READING | PA |
| PENNSYLVANIA HOSPITAL | PHILADELPHIA | PA |
| PENNSYLVANIA INDUSTRIAL CHEMICAL CO – CHESTER PLANT | CHESTER | PA |
| PENNSYLVANIA INDUSTRIAL CHEMICAL CO – CLAIRTON PLANT | CLAIRTON | PA |
| PENNSYLVANIA INDUSTRIAL CHEMICAL CO – CLAIRTON PLANT STOREROOM | CLAIRTON | PA |
| PENNSYLVANIA INDUSTRIAL CHEMICAL CO – GATE 1 | CHESTER | PA |
| PENNSYLVANIA INDUSTRIAL CHEMICAL CO – JEFFERSON PLANT | WEST ELIZABETH | PA |
| PENNSYLVANIA INSTITUTE FOR INSTRUCTION OF BLIND | OVERBROOK | PA |
| PENNSYLVANIA INSTITUTE FOR THE INSTRUCTION OF THE BLIND | PHILADELPHIA | PA |
| Pennsylvania Iron Co. | Lancaster | PA |
| PENNSYLVANIA LEIGHTWEIGHT AGGREGATE | BANGOR | PA |
| PENNSYLVANIA LIGHT AND POWER COMPANY | ALLEGHENY | PA |
| PENNSYLVANIA LIGHT, HEAT AND POWER COMPANY | ALLEGHENY | PA |
| PENNSYLVANIA LINES, WEST OF PITTSBURGH, ALLEGHENY SHOPS | ALLEGHENY | PA |
| PENNSYLVANIA LUBRICATING COMPANY | PITTSBURGH | PA |
| PENNSYLVANIA MALLEABLE COMPANY | PITTSBURGH | PA |
| PENNSYLVANIA MALLEABLE COMPANY | MCKEES ROCKS | PA |
| PENNSYLVANIA MANUFACTURING LIGHT AND POWER COMPANY | PHILADELPHIA | PA |
| PENNSYLVANIA MANUFACTURING, LIGHT AND POWER COMPANY | PHILADELPHIA | PA |
| PENNSYLVANIA MUTUAL BUILDING | PHILADELPHIA | PA |
| PENNSYLVANIA MUTUAL INSURANCE COMPANY – 5TH & WALNUT STREETS | PHILADELPHIA | PA |
| Pennsylvania Ordnance | Allenwood | PA |
| Pennsylvania Ordnance Works (Susquehanna Ordnance Works) | Allentown | PA |
| PENNSYLVANIA PERLITE CORPORATION – MANUFACTURING PLANT | BETHLEHEM | PA |
| PENNSYLVANIA POWER | WEST PITTSBURGH | PA |
| Pennsylvania Power & Light | Martins Creek | PA |
| PENNSYLVANIA POWER & LIGHT | ALLENTOWN | PA |
| PENNSYLVANIA POWER & LIGHT | BRUNNERS ISLAND | PA |
| PENNSYLVANIA POWER & LIGHT | MANSFIELD | PA |
| PENNSYLVANIA POWER & LIGHT | SUNBURY | PA |
| PENNSYLVANIA POWER & LIGHT | SHAMOKIN DAM | PA |
| PENNSYLVANIA POWER & LIGHT | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT – BRUNNER ISLAND PLANT | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT – BRUNNER ISLAND PLANT – UNIT #2 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT – BRUNNER ISLAND PLANT – UNIT #3 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT – HOLTWOOD STATION | HOLTWOOD | PA |
| PENNSYLVANIA POWER & LIGHT – LANCASTER COUNTY | HOLTWOOD | PA |
| PENNSYLVANIA POWER & LIGHT – MONTOUR POWER PLANT | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT – MONTOUR STATION | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT – MONTOUR STATION – UNIT #1 | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT – MONTOUR STATION – UNIT #2 | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT – SUNBURY | SHAMOKIN DAM | PA |
| PENNSYLVANIA POWER & LIGHT – TURBINE | SHAMOKIN DAM | PA |
| PENNSYLVANIA POWER & LIGHT CO | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER #1 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER ISLAND | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER ISLAND STATION | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER ISLAND STATION – UNIT 2 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER ISLAND STATION UNIT NBR 3 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER ISLAND STEAM ELEC STATION – UNIT NBR 2 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER ISLAND STEAM STATION | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – BRUNNER ISLAND UNIT NBR 3 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – DRUNNER ISLAND STATION | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT CO – GENERATION STORES – ENGLESIDE SERVICE DEPOT | LANCASTER | PA |
| PENNSYLVANIA POWER & LIGHT CO – MARTINS | MARTINS CREEK | PA |
| PENNSYLVANIA POWER & LIGHT CO – MARTINS CREEK S E S | MARTINS CREEK | PA |
| PENNSYLVANIA POWER & LIGHT CO – MONTOUR | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT CO – MONTOUR NO 1 POWER PLANT | STRAWBERRY RIDGE | PA |
| PENNSYLVANIA POWER & LIGHT CO – MONTOUR NO 1 POWER PLANT | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT CO – MONTOUR STEAM ELEC STATION UNIT 1 | STRAWBERRY RIDGE | PA |
| PENNSYLVANIA POWER & LIGHT CO – MONTOUR STEAM ELEC STATION UNIT 2 | STRAWBERRY RIDGE | PA |
| PENNSYLVANIA POWER & LIGHT CO – MONTOUR STEAM ELEC STATION UNIT 2 | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT CO – POWER PLANT STOREROOM | SHAMOKIN DAM | PA |
| PENNSYLVANIA POWER & LIGHT CO – POWER PLANT STOREROOM | SNYDER CTY | PA |
| PENNSYLVANIA POWER & LIGHT CO – R. H. WHETSTONE SUPT | PINE GROVE | PA |
| PENNSYLVANIA POWER & LIGHT CO – SES STATION | MARTINS CREEK | PA |
| PENNSYLVANIA POWER & LIGHT CO – SUBURBAN PLANT STOREROOM | SCRANTON | PA |
| PENNSYLVANIA POWER & LIGHT CO – SUNBURY S E S | SHAMOKIN DAM | PA |
| Pennsylvania Power & Light Co. | Sunbury | PA |
| Pennsylvania Power & Light Co. | York Haven | PA |
| PENNSYLVANIA POWER & LIGHT CO. – BRUNNER ISLAND STATION | YORK HAVEN | PA |
| Pennsylvania Power & Light Co. – Cedar Steam Electric Station | Harrisburg | PA |
| Pennsylvania Power & Light Co. (a/k/a Lehigh Valley P&L) – Hauto Steam Electric Station | Hauto | PA |
| Pennsylvania Power & Light Co. (a/k/a Phoenix Utility) – Walnut Steam Heat Station | Harrisburg | PA |
| Pennsylvania Power & Light Co.- Sunbury Steam Station | Shamokin Dam | PA |
| Pennsylvania Power & Light Co., Unit #2 | Martins Creek | PA |
| Pennsylvania Power & Light Co.? Martins Creek Power Plant | Martins Creek | PA |
| Pennsylvania Power & Light Company | Pine Groove | PA |
| Pennsylvania Power & Light Company | Shamokin Dam | PA |
| PENNSYLVANIA POWER & LIGHT COMPANY | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT COMPANY | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT, BRUNNER ISLAND PLANT | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT, BRUNNER ISLAND PLANT, UNIT #2 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT, BRUNNER ISLAND PLANT, UNIT #3 | YORK HAVEN | PA |
| PENNSYLVANIA POWER & LIGHT, HOLTWOOD STATION | HOLTWOOD | PA |
| PENNSYLVANIA POWER & LIGHT, LANCASTER COUNTY | HOLTWOOD | PA |
| PENNSYLVANIA POWER & LIGHT, MONTOUR STATION | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT, MONTOUR STATION, UNIT #1 | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT, MONTOUR STATION, UNIT #2 | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT, MONTOUR STEAM ELECTRIC STATION, UNIT # 1 EBASCO SERVICES, INC. AGENT | WASHINGTONVILLE | PA |
| PENNSYLVANIA POWER & LIGHT, MONTOUR STEAM ELECTRIC STATION, UNIT # 2 EBASCO SERVICES, INC. AGENT | STRAWBERRY RIDGE | PA |
| PENNSYLVANIA POWER & LIGHT, SUNBURY | SHAMOKIN DAM | PA |
| PENNSYLVANIA POWER & LIGHT, TURBINE | HARRISBURG | PA |
| PENNSYLVANIA POWER & LIGHT, TURBINE | PITTSBURGH | PA |
| PENNSYLVANIA POWER & LIGHT, TURBINE | SHAMOKIN DAM | PA |
| Pennsylvania Power and Light | Martin’s Creek | PA |
| Pennsylvania Power and Light – Lower Mount Bethel Energy Plant | Lower Mount Bethel | PA |
| Pennsylvania Power and Light – Unit No. 2 | Brunner Island | PA |
| PENNSYLVANIA POWER AND LIGHT (PPL) – BRUNNER ISLAND STEAM ELECTRIC STATION | YORK COUNTY | PA |
| PENNSYLVANIA POWER AND LIGHT (PPL) – MARTINS CREEK POWER PLANT | HARRISBURG | PA |
| PENNSYLVANIA POWER AND LIGHT (PPL) BUILDING – NORTH 9TH STREET | ALLENTOWN | PA |
| PENNSYLVANIA POWER AND LIGHT COMPANY | HAUTO | PA |
| PENNSYLVANIA POWER AND LIGHT COMPANY | RIVER STATION | PA |
| PENNSYLVANIA POWER AND LIGHT COMPANY | SCRANTON | PA |
| Pennsylvania Power and Light Company – Hauto Steam Electric Station | HAUTO | PA |
| PENNSYLVANIA POWER CO., CONSTRUCTION DEPT., FIELD OFFICE, BRUCE MANSFIELD PLANT, UNIT #3 | SHIPPINGPORT | PA |
| PENNSYLVANIA POWER COMPANY | ELLWOOD CITY | PA |
| PENNSYLVANIA POWER COMPANY | NEW CASTLE | PA |
| PENNSYLVANIA POWER COMPANY – NEW CASTLE PLANT | NEW CASTLE | PA |
| PENNSYLVANIA POWER COMPANY, NEW CASTLE PLANT | WEST PITTSBURGH | PA |
| Pennsylvania Power- Shippingport Atomic Power Station | Shippingport | PA |
| PENNSYLVANIA PULP AND PAPER COMPANY | LOCK HAVEN | PA |
| PENNSYLVANIA RAIL ROAD SHOPS | WEST PHILADELPHIA | PA |
| Pennsylvania Railroad | Balairsville | PA |
| Pennsylvania Railroad | Pitcairn | PA |
| Pennsylvania Railroad | Shire Oaks | PA |
| PENNSYLVANIA RAILROAD | PAOLI | PA |
| PENNSYLVANIA RAILROAD | MEDIA | PA |
| PENNSYLVANIA RAILROAD | JUANITA | PA |
| PENNSYLVANIA RAILROAD | ERIE | PA |
| PENNSYLVANIA RAILROAD | CHESTER | PA |
| PENNSYLVANIA RAILROAD | HOLIDAYSBURG | PA |
| PENNSYLVANIA RAILROAD – BROAD STREET STATION | PHILADELPHIA | PA |
| PENNSYLVANIA RAILROAD CO | PHILADELPHIA | PA |
| PENNSYLVANIA RAILROAD CO | ALTOONA | PA |
| PENNSYLVANIA RAILROAD CO – Steam Heating Plant, 30th & Race St. | WEST PHILADELPHIA | PA |
| Pennsylvania Railroad Co. | Philadelphia | PA |
| PENNSYLVANIA RAILROAD CO. – JUNIATA SHOP | ALTOONA | PA |
| PENNSYLVANIA RAILROAD CO. – STATION 1560 – JUNIATA SHOP | ALTOONA | PA |
| Pennsylvania Railroad Company | Altoona | PA |
| Pennsylvania Railroad Company | East Altoona | PA |
| Pennsylvania Railroad Company | Enola | PA |
| Pennsylvania Railroad Company | Philadelphia | PA |
| Pennsylvania Railroad Company | Pittsburgh | PA |
| PENNSYLVANIA RAILROAD COMPANY | RENOVO | PA |
| PENNSYLVANIA RAILROAD COMPANY | RONOVO | PA |
| PENNSYLVANIA RAILROAD COMPANY | WEST PHILADELPHIA | PA |
| PENNSYLVANIA RAILROAD COMPANY | ERIA | PA |
| PENNSYLVANIA RAILROAD COMPANY | LAWRENCE JUNCTION | PA |
| PENNSYLVANIA RAILROAD COMPANY | POTTSVILLE | PA |
| PENNSYLVANIA RAILROAD COMPANY | READING | PA |
| PENNSYLVANIA RAILROAD COMPANY | SOUTH ALTOONA | PA |
| PENNSYLVANIA RAILROAD COMPANY | ST. ALTOONA | PA |
| PENNSYLVANIA RAILROAD COMPANY | PITCAIRN | PA |
| PENNSYLVANIA RAILROAD COMPANY 28TH ST. POWERHOUSE | PITTSBURGH | PA |
| PENNSYLVANIA RAILROAD COMPANY, CAR SHOPS | ALTOONA | PA |
| PENNSYLVANIA RAILROAD COMPANY, FOUNDRIES | ALTOONA | PA |
| PENNSYLVANIA RAILROAD OFFICE | PHILADELPHIA | PA |
| PENNSYLVANIA RAILROAD SAMUEL REA CAR REPAIR SHOP | HOLLIDAYSBURG | PA |
| PENNSYLVANIA RAILROAD SHOPS | RENOVO | PA |
| Pennsylvania Railroad Station | Pittsburgh | PA |
| PENNSYLVANIA RAILROAD, BROAD ST. STATION, GERMANTOWN JUNCTION, WOODLAND AV. FREIGHT | PHILADELPHIA | PA |
| Pennsylvania Railroad, Freight Station | Harrisburg | PA |
| Pennsylvania Range Boiler | Philadelphia | PA |
| PENNSYLVANIA REFINING COMPANY – BLDG 38-31 | KARNS CITY | PA |
| PENNSYLVANIA REFINING COMPANY – KARNS CITY REFINERY | KARNS CITY | PA |
| PENNSYLVANIA REFINING COMPANY – NEAR BUTLER, PA. | KARNS CITY | PA |
| Pennsylvania Rubber Co. | Jeanette | PA |
| PENNSYLVANIA RUBBER COMPANY | JEANNETTE | PA |
| PENNSYLVANIA RUBBER COMPANY | ERIE | PA |
| PENNSYLVANIA SALIGHT MANUFACTURING COMPANY | NATRONA | PA |
| PENNSYLVANIA SALT MANUFACTURING COMPANY | NATRONA | PA |
| PENNSYLVANIA SALT MFG. CO. | WYNDMOOR | PA |
| Pennsylvania Smelting & Refining Co. | Philadelphia | PA |
| PENNSYLVANIA STATE HOSPITAL FOR TUBERCULOSIS | HAMBURG | PA |
| PENNSYLVANIA STATE HOSPITAL TUBERCULOSIS SANATORIUM #4 | PHILADELPHIA | PA |
| PENNSYLVANIA STATE PARK – RACOON STATE PARK – DEPT OF PROPERTY & SUPPLY PROJECT | PITTSBURGH | PA |
| PENNSYLVANIA STATE REFORM SCHOOL | MORGANZA | PA |
| PENNSYLVANIA STATE TRAINING SCHOOL | MORGANZA | PA |
| PENNSYLVANIA STATE UNIV. – 104 ENGINEERING D BLDG. | STATE COLLEGE | PA |
| PENNSYLVANIA STATE UNIVERSITY – ENGINEERING RESEARCH DEPT. – 104 ENGINEERING D BLDG. – UNIVERSITY PARK, PENNSYLVANIA | STATE COLLEGE | PA |
| Pennsylvania Steel | Chester | PA |
| PENNSYLVANIA STEEL COMPANY | STEELTON | PA |
| PENNSYLVANIA STEEL COMPANY | LEBANON | PA |
| PENNSYLVANIA STEEL COMPANY | PHILADELPHIA | PA |
| PENNSYLVANIA STEEL COMPANY, COKE OVENS | STEELTON | PA |
| PENNSYLVANIA STEEL COMPANY, LEBANON FURNACE | LEBANON | PA |
| PENNSYLVANIA STEEL MILL | CHESTER | PA |
| PENNSYLVANIA SUGAR | PHILADELPHIA | PA |
| Pennsylvania Sugar Co | Philadelphia | PA |
| PENNSYLVANIA SUGAR COMPANY | PHILADELPHIA | PA |
| PENNSYLVANIA SUGAR DIVISION, NATIONAL SUGAR REFINING COMPANY | PHILADELPHIA | PA |
| PENNSYLVANIA TRAINING SCHOOL | MORGANZA | PA |
| PENNSYLVANIA TUBE COMPANY | PITTSBURGH | PA |
| PENNSYLVANIA TURNPIKE | HARRISBURG | PA |
| Pennsylvania Utilities Co. | Easton | PA |
| PENNSYLVANIA UTILITIES COMPANY – DOCK STREET PLANT | EASTON | PA |
| PENNSYLVANIA WATER AND POWER COMPANY – HOLTWOOD HYDROELECTRIC POWER PLANT | HOLTWOOD | PA |
| PENNSYLVANIA WATER COMPANY – FILTRATION PLANT | WILKINSBURG | PA |
| PENNSYLVANIA WATER COMPANY – PUMPING STATION | WILDWOOD | PA |
| PENNSYLVANIA WATER COMPANY – PUMPING STATION | NADINE | PA |
| PENNSYLVANIA, COMMONWEALTH | SLIPPERY ROCK | PA |
| Pennsylvannia Electric Company – Seward Station | Seward | PA |
| PENNSYLVNIA COMPANY | PITTSBURGH | PA |
| Penntech Papers Inc | Johnsonburg | PA |
| PENNTECH PAPERS INC (a/k/a New York & Penn Co., Inc.) | JOHNSONBURG | PA |
| Pennwalt Corp. | Philadelphia | PA |
| PENNWEST FUELS | CLYMER | PA |
| PENNZOIL | ROUSEVILLE | PA |
| PENNZOIL CO – PLANT 1 | ROUSEVILLE | PA |
| PENNZOIL CO – PLANT 2 | OIL CITY | PA |
| PENNZOIL CO – PLANT NO. 2 | OIL CITY | PA |
| Pennzoil Company | Rouserville | PA |
| PENNZOIL COMPANY | PITTSBURGH | PA |
| PENNZOIL COMPANY | OIL CITY | PA |
| Pennzoil Refinery | Oil City | PA |
| PENNZOIL REFINING CO. – PLANT NO. 1 | ROUSEVILLE | PA |
| PENRECO/PENNSYLVANIA REFINING CO | KARNS CITY | PA |
| PENSYLVANIA FORGE CORP | TACONY PHILADELPHIA | PA |
| PENZOIL CO SOUTH PENN OI | OIL CITY | PA |
| PENZOIL COMPANY, PLANT #4 | HOUSERVILLE | PA |
| PENZOLL REFINERY | OIL CITY | PA |
| People Natural Gas | White Valley | PA |
| PEOPLE TRACTION COMPANY | PHILADELPHIA | PA |
| PEOPLES BANK | WILKES BARRE | PA |
| Peoples Bank Building | Pittsburgh | PA |
| PEOPLES COAL COMPANY | OXFORD SWITCH | PA |
| PEOPLES COAL COMPANY | SCRANTON | PA |
| PEOPLES CONSOLIDATED SERVICE CORPORATION | EASTON | PA |
| PEOPLES ELECTRIC LIGHT, HEAT AND POWER COMPANY – HEATING PLANT | GREENVILLE | PA |
| PEOPLES ICE AND COLD STORAGE COMPANY | MCKEESPORT | PA |
| PEOPLES ICE COLD STORAGE COMPANY | MCKEESPORT | PA |
| PEOPLES ICE LIGHT AND STORAGE COMPANY | MCKEESPORT | PA |
| PEOPLES INCANDESCENT LIGHT AND POWER COMPANY | MEADVILLE | PA |
| PEOPLES LAND COMPANY | PITTSBURGH | PA |
| PEOPLES LIGHT HEAT AND POWER COMPANY | MAHONEY CITY | PA |
| PEOPLES NATURAL GAS – BRAVE STATION | BRAVE | PA |
| PEOPLES NATURAL GAS CO. | TEANNETTE | PA |
| PEOPLES NATURAL GAS COMPANY – OFFICE BUILDING | WILKINSBURG | PA |
| PEOPLES POWER COMPANY | ELWOOD CITY | PA |
| Peoples Savings & Trust Building | Pittsburgh | PA |
| PEOPLES STREET RAILWAY COMPANY | ALDEN | PA |
| PEOPLES STREET RAILWAY COMPANY | WANAMIE | PA |
| PEOPLES STREET RAILWAY COMPANY | NANTICOKE | PA |
| PEP BOYS | PHILADELPHIA | PA |
| PEPPERIDGE FARMS | DOWNINGTON | PA |
| PERKINS AND COMPANY, LIMITED | SHARPSVILLE | PA |
| PERLSTEIN GLASS COMPANY – RICHMOND STREET | PHILADELPHIA | PA |
| PERREX ALUMINUM | WELLSVILLE | PA |
| PERRY IRON COMPANY | ERIE | PA |
| PERRY LOWER TYRONE SCHOOL | FAYETTE COUNTY | PA |
| PERRY SHIP BUILDERS COMPA | ERIE | PA |
| Pes Valley Insulation Co | Lester | PA |
| PETER F. LOFTUS | PITTSBURGH | PA |
| PETERS AND COMPANY | MCKEESPORT | PA |
| PETERS PACKING COMPANY | MCKEESPORT | PA |
| PETERS PACKING COMPANY | KEESPORT | PA |
| Petroleum Iron Works | Sharon | PA |
| Petroleum Reclamation Company | Bradford | PA |
| PETROWAX | EMLENTON | PA |
| PETROWAX | FARMERS VALLEY | PA |
| PFIZER INCORPORATED | EASTON | PA |
| PGH Transformer | Canonsburg | PA |
| PGW – TORRESDALE | PHILADELPHIA | PA |
| PHIL ELLENA AND CHEW STS. | PHILADELPHIA | PA |
| PHILADELPHIA AND BRISTOL WATER COMPANY – WATER FILTRATION PLANT | HOLMESBURG | PA |
| PHILADELPHIA AND READING COAL AND IRON COMPANY | POTTSVILLE | PA |
| PHILADELPHIA AND READING COAL AND IRON COMPANY | GOOD SPRING | PA |
| PHILADELPHIA AND READING COAL AND IRON COMPANY | LOCUST GAP | PA |
| PHILADELPHIA AND READING COAL AND IRON COMPANY | ST. NICHOLAS | PA |
| PHILADELPHIA AND READING COAL AND IRON COMPANY | MINERSVILLE | PA |
| PHILADELPHIA AND READING COAL AND IRON COMPANY | PHILADELPHIA | PA |
| PHILADELPHIA AND READING COAL AND IRON COMPANY | MT. CARMEL | PA |
| PHILADELPHIA AND READING RAILROAD COMPANY | PHILADELPHIA | PA |
| PHILADELPHIA AND READING RAILROAD COMPANY | MAHANOY PLANE | PA |
| PHILADELPHIA AND READING RAILROAD COMPANY | READING | PA |
| PHILADELPHIA AND READING RAILWAY | PHILADELPHIA | PA |
| PHILADELPHIA AND READING RAILWAY | READING | PA |
| PHILADELPHIA AND READING RAILWAY COMPANY | FRACKVILLE | PA |
| PHILADELPHIA AND READING SUBWAY | PHILADELPHIA | PA |
| PHILADELPHIA AQUATIC CLUB | PHILADELPHIA | PA |
| Philadelphia Asbestos & Cork | Philadelphia | PA |
| Philadelphia Asbestos Co | Philadelphia | PA |
| PHILADELPHIA ASBESTOS COR | PHILADELPHIA | PA |
| Philadelphia Asbestos Corp. | Philadelphia | PA |
| PHILADELPHIA BANK BUILDING | PHILADELPHIA | PA |
| PHILADELPHIA BOARD OF EDUCATION | PHILADELPHIA | PA |
| Philadelphia Brewing Co. | Philadelphia | PA |
| PHILADELPHIA BURNER SERV | PHILADELPHIA | PA |
| PHILADELPHIA CITY HALL ANNEX | PHILADELPHIA | PA |
| Philadelphia Coke Co | Philadelphia | PA |
| Philadelphia Coke Co. | Philadelphia | PA |
| PHILADELPHIA COKE COMPANY | PHILADELPHIA | PA |
| PHILADELPHIA COLLEGE OF A | PHILADELPHIA | PA |
| PHILADELPHIA COLLEGE OF ARTS | PHILADELPHIA | PA |
| PHILADELPHIA COMPANY | CANONSBURG | PA |
| PHILADELPHIA COMPANY | PITTSBURGH | PA |
| PHILADELPHIA COMPANY OF PITTSBURGH | PITTSBURGH | PA |
| PHILADELPHIA CONVENTION HALL | PHILADELPHIA | PA |
| PHILADELPHIA CONVENTION HALL (MUNICIPAL AUDITORIUM) | PHILADELPHIA | PA |
| PHILADELPHIA COUNTY PRISON | HOLMESBURG | PA |
| PHILADELPHIA COUNTY PRISON | PHILADELPHIA | PA |
| PHILADELPHIA COUNTY PRISON | MOYAMENSING | PA |
| PHILADELPHIA DRY YEAST | PHILADELPHIA | PA |
| PHILADELPHIA DYE WORKS | PHILADELPHIA | PA |
| Philadelphia Electric | Falls Twp | PA |
| Philadelphia Electric | Phoenixville | PA |
| Philadelphia Electric | Sanatoga | PA |
| Philadelphia Electric | Philadelphia | PA |
| Philadelphia Electric | Briston Twp | PA |
| Philadelphia Electric | Pottstown | PA |
| PHILADELPHIA ELECTRIC | CHESTER | PA |
| Philadelphia Electric – Barbadoes Station | West Norriton | PA |
| PHILADELPHIA ELECTRIC – BRUNNER ISLAND | YORK HAVEN | PA |
| Philadelphia Electric – Cromby Station | E. Pikeland Township | PA |
| Philadelphia Electric – Eddystone Station | Eddystone | PA |
| PHILADELPHIA ELECTRIC – PEACHBOTTOM NUCLEAR | DELTA | PA |
| Philadelphia Electric – Richmond Station | Philadelphia | PA |
| PHILADELPHIA ELECTRIC – SCHUYLKILL GENERATING STATION | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC – SCHUYLKILL GENERATING STATION – STEAMLINE AND MANHOLE | PHILADELPHIA | PA |
| Philadelphia Electric – Schuylkill Station | Philadelphia | PA |
| Philadelphia Electric Co | Philadelphia | PA |
| Philadelphia Electric Co | Chester | PA |
| Philadelphia Electric Co 9th & Willow Streets | Philadelphia | PA |
| Philadelphia Electric Co Cromby Station | Philadelphia | PA |
| Philadelphia Electric Co Delaware Station | Philadelphia | PA |
| Philadelphia Electric Co Eddystone 1 | Philadelphia | PA |
| Philadelphia Electric Co. | Eddystone | PA |
| Philadelphia Electric Co. | Conowingo | PA |
| Philadelphia Electric Co. | Chester | PA |
| PHILADELPHIA ELECTRIC CO. | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC CO. – EDDYSTONE GENERATING STATION | Crum Creek | PA |
| PHILADELPHIA ELECTRIC CO. – EDISON HEATING PLANT – UNIT 3 | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC CO. – RICHMOND STATION | PHILADELPHIA | PA |
| Philadelphia Electric Co.- Peach Bottom Power Station | Delta | PA |
| Philadelphia Electric Co., Crombie Station | Phoenixville | PA |
| Philadelphia Electric Co., Delaware Sta. | Philadelphia | PA |
| Philadelphia Electric Company | Philadelphia | PA |
| Philadelphia Electric Company | West Conshohocken | PA |
| Philadelphia Electric Company | Peach Botom | PA |
| Philadelphia Electric Company | Chester | PA |
| Philadelphia Electric Company | Eddystone | PA |
| Philadelphia Electric Company – Barbadoes Island Power Plant | Barbadoes Island | PA |
| PHILADELPHIA ELECTRIC COMPANY – BARBADOS ISLAND | BARBADOS ISLAND | PA |
| PHILADELPHIA ELECTRIC COMPANY – CHESTER STATION POWER PLANT | CHESTER | PA |
| Philadelphia Electric Company – Cromby Generating Station | Phoenixville | PA |
| PHILADELPHIA ELECTRIC COMPANY – CROMBY STATION | PHOENIXVILLE | PA |
| Philadelphia Electric Company – Delaware Generating Station | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – DELAWARE STATION | PHILADELPHIA | PA |
| Philadelphia Electric Company – Eddystone Generating Station | Eddystone | PA |
| Philadelphia Electric Company – Eddystone Station | Eddystone | PA |
| PHILADELPHIA ELECTRIC COMPANY – EDISON STEAM PLANT – 9TH & SANSOM | PHILADELPHIA | PA |
| Philadelphia Electric Company – Limerick Generating Station | Pottstown | PA |
| Philadelphia Electric Company – Peach Bottom Atomic Power Station | DELTA | PA |
| Philadelphia Electric Company – Peach Bottom Atomic Power Station – Unit 2 | DELTA | PA |
| Philadelphia Electric Company – Peach Bottom Atomic Power Station – Unit 3 | DELTA | PA |
| Philadelphia Electric Company – PECO Building – 23RD & MARKET STREETS | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – POWER PLANT | CROMBY | PA |
| PHILADELPHIA ELECTRIC COMPANY – RICHMOND FACILITY – FUEL OIL FACILITY | PHILADELPHIA | PA |
| Philadelphia Electric Company – Richmond Generating Station | Philadelphia | PA |
| PHILADELPHIA ELECTRIC COMPANY – RICHMOND STATION | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – RICHMOND STATION – CRUDE OIL FACILITY | PHILADELPHIA | PA |
| Philadelphia Electric Company – Schuylkill Generating Station | Philadelphia | PA |
| PHILADELPHIA ELECTRIC COMPANY – SCHUYLKILL STATION | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – SCHUYLKILL STATION – 28TH & CHRISTIAN | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – SOUTHWARK POWER PLANT | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – STATION C | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – STATION J | TACONY | PA |
| PHILADELPHIA ELECTRIC COMPANY – TACONY POWER PLANT | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY – WEST CONSHOHOCKEN GAS PLANT | WEST CONSHOHOCKEN | PA |
| Philadelphia Electric Company – Willow Street steam Plant | PHILADELPHIA | PA |
| PHILADELPHIA ELECTRIC COMPANY BUILDING | PHILADELPHIA | PA |
| Philadelphia Electric Company- Chester Generating Station | Chester | PA |
| PHILADELPHIA ELECTRIC COR | PHILADELPHIA | PA |
| Philadelphia Electric Plant Barbadoes Island | Philadelphia | PA |
| Philadelphia Electric Richmond | Philadelphia | PA |
| PHILADELPHIA ENGINEERING COMPANY | PHILADELPHIA | PA |
| PHILADELPHIA EXPOSITION | PHILADELPHIA | PA |
| Philadelphia Fire Department | Philadelphia | PA |
| Philadelphia Forge | Philadelphia | PA |
| Philadelphia Forge Co. | Philadelphia | PA |
| PHILADELPHIA GAS WORKS | PHILADELPHIA | PA |
| PHILADELPHIA GAS WORKS – 31ST & PASSYUNK AVENUE | PHILADELPHIA | PA |
| Philadelphia Gas Works – Passyunk Ave Plant | PHILADELPHIA | PA |
| Philadelphia Gas Works – Station A | Philadelphia | PA |
| Philadelphia Gas Works – Station B | Philadelphia | PA |
| Philadelphia Gas Works Station A & B | Philadelphia | PA |
| PHILADELPHIA GEAR WORKS | KING OF PRUSSIA | PA |
| Philadelphia General Hospital | Philadelphia | PA |
| PHILADELPHIA GENERAL HOSPITAL – MEDICAL EXAMINERS LABORATORY | PHILADELPHIA | PA |
| PHILADELPHIA GENERAL HOSPITAL – STUDENT NURSES DORMITORY | PHILADELPHIA | PA |
| PHILADELPHIA GENERAL HOSPITAL, MEDICAL EXAMINERS LABORATORY | PHILADELPHIA | PA |
| PHILADELPHIA GREYHOUND TERMINAL | PHILADELPHIA | PA |
| PHILADELPHIA GROUP – ATLANTIC RESERVE FLEET NAVAL BASE | PHILADELPHIA | PA |
| PHILADELPHIA HIGH SCHOOL FOR GIRLS – WEST OLNEY AVENUE | PHILADELPHIA | PA |
| PHILADELPHIA HOME FOR INDIGENT & | PHILADELPHIA | PA |
| PHILADELPHIA HOSPITAL | PHILADELPHIA | PA |
| PHILADELPHIA HOSPITAL FOR THE INSANE | PHILADELPHIA | PA |
| PHILADELPHIA HOSPITAL FOR THE INSANE, MALE DEPARTMENT | PHILADELPHIA | PA |
| PHILADELPHIA HOUSING AUTH | PHILADELPHIA | PA |
| PHILADELPHIA HOUSING AUTHORITY | PHILADELPHIA | PA |
| PHILADELPHIA INCINERATOR | PHILADELPHIA | PA |
| PHILADELPHIA INQUIRER | PHILADELPHIA | PA |
| Philadelphia Inquirer Office Building | Philadelphia | PA |
| Philadelphia Institute for Feeble Minded | Byberry | PA |
| PHILADELPHIA INTERNATIONAL AIRPORT | PHILADELPHIA | PA |
| Philadelphia Ironworks | Philadelphia | PA |
| PHILADELPHIA MORTON AND SWARTHMORE STREET RAILWAY | FOLSOM STATION | PA |
| PHILADELPHIA MUSEUM | PHILADELPHIA | PA |
| Philadelphia National Bank | Philiadelphia | PA |
| Philadelphia Naval Base | Philadelphia | PA |
| Philadelphia Naval Shipyard | Philadelphia | PA |
| PHILADELPHIA NAVAL SHIPYARD | USS LOS ANGELES | PA |
| PHILADELPHIA NAVAL SHIPYARD | USS NEW JERSEY | PA |
| PHILADELPHIA NAVAL SHIPYARD | USS VALLEY FORGE | PA |
| PHILADELPHIA NAVAL SHIPYARD | USS WASHINGTON | PA |
| PHILADELPHIA NAVAL SHIPYARD – BLDG 624 | PHILADELPHIA | PA |
| PHILADELPHIA NAVAL SHIPYARD – BUILDING 624 | PHILADELPHIA | PA |
| Philadelphia Navy Yard | Philadelphia | PA |
| PHILADELPHIA NAVY YARD TRAINING SCHOOL | PHILADELPHIA | PA |
| PHILADELPHIA PIPING & EQUIPMENT CO. – BLDG 64 – WING A EXT | BRISTOL | PA |
| PHILADELPHIA PIPING & EQUIPMENT CO. – WRIGHTSTOWN ELEMENTARY SCHOOL – PENNS PARK | BUCKS COUNTY | PA |
| PHILADELPHIA PROTECTORY FOR BOYS | PHOENIXVILLE | PA |
| PHILADELPHIA PSYCHIATRIC HOSPITAL | PHILADELPHIA | PA |
| PHILADELPHIA PUBLIC LIBRARY | PHILADELPHIA | PA |
| PHILADELPHIA QUARTZ CO | PHILADELPHIA | PA |
| PHILADELPHIA QUARTZ COMPANY | PHILADELPHIA | PA |
| PHILADELPHIA QUARTZ COMPANY | CHESTER | PA |
| PHILADELPHIA RAILROAD | READING | PA |
| PHILADELPHIA READING COAL AND IRON COMPANY | MAHANOY PLANE | PA |
| PHILADELPHIA READING CORPORATION | POTTSVILLE | PA |
| Philadelphia Resin Company | Philadelphia | PA |
| Philadelphia Roll & Machine | Philadelphia | PA |
| PHILADELPHIA RUBBER WORKS COMPANY | OAKS | PA |
| PHILADELPHIA RUST | PHILADELPHIA | PA |
| PHILADELPHIA RUST PROOF C | PHILADELPHIA | PA |
| PHILADELPHIA S&C 10 | BERWYN | PA |
| PHILADELPHIA S&C 10 – CUSTOMER PICK UP | BERWYN | PA |
| Philadelphia School District | Philadelphia | PA |
| PHILADELPHIA SHIP MAINTEN | PHILADELPHIA | PA |
| PHILADELPHIA SHIPYARD | PHILADELPHIA | PA |
| PHILADELPHIA ST HOSPITAL | PHILADELPHIA | PA |
| PHILADELPHIA SUBURBAN GAS AND ELECTRIC COMPANY – GAS PLANT | JENKINTOWN | PA |
| PHILADELPHIA SUBURBAN GAS AND ELECTRIC COMPANY – POWER PLANT | WEST CHESTER | PA |
| Philadelphia Suburban Water Co. | Janney | PA |
| PHILADELPHIA SUBURBAN WATER COMPANY – WATER FILTRATION PLANT | CRUM CREEK | PA |
| PHILADELPHIA TAPESTRY MILLS | PHILADELPHIA | PA |
| PHILADELPHIA TRACTION COMPANY | PHILADELPHIA | PA |
| PHILADELPHIA WOOL SCOURIN | PHILADELPHIA | PA |
| PHILADELPHIA ZOO | PHILADELPHIA | PA |
| Philadelphia Zoo – Rare Mammal House | Philadelphia | PA |
| PHILADELPHIA, CITY OF | PHILADELPHIA | PA |
| PHILADELPHIADELPHIA AND READING COAL AND IRON COMPANY | POTTSVILLE | PA |
| PHILADELPHIADELPHIA AND READING COAL AND IRON COMPANY | SCHUYKILL HAVEN | PA |
| Philco | Blue Bell | PA |
| PHILIP CAREY MANUFACTURING COMPANY | PLYMOUTH MEETING | PA |
| PHILIP CAREY MANUFACTURING PLANT | PLYMOUTH MEETING | PA |
| PHILIPSBURG STATE HOSPITAL – REHABILITATION ANNEX | PHILIPSBURG | PA |
| PHILLIP CAREY | PLYMOUTH | PA |
| PHILLIP CAREY MANUFACTURING COMPANY | PHILADELPHIA | PA |
| Phillips Generating Station | South Heights | PA |
| Phillips Petroleum Co | Hanover | PA |
| PHILLIPS POWER STATION | SOUTH HEIGHTS | PA |
| PHILMOND ASSOCIATION AND WEST AV INVS | HUNTINGDON VALLEY | PA |
| PHOENIX CEMENT COMPANY | NAZARETH | PA |
| PHOENIX GLASS | MONACA | PA |
| PHOENIX GLASS COMPANY | MONACA | PA |
| PHOENIX GLASS COMPANY | PITTSBURGH | PA |
| PHOENIX IRON AND STEEL COMPANY | CHESTER | PA |
| PHOENIX IRON AND STEEL COMPANY | HARRISBURG | PA |
| PHOENIX IRON AND STEEL COMPANY, BLAST FURNACE DIVISION | CHESTER | PA |
| PHOENIX IRON COMPANY | PHOENIXVILLE | PA |
| PHOENIX STEEL | PHOENIXVILLE | PA |
| Phoenix Steel Corp | Phoenixville | PA |
| PHOENIX STEEL CORPORATION | PHOENIXVILLE, CHESTER COUNTY | PA |
| Phoenix Utility Company | Williamsport | PA |
| PHOENIX UTILITY COMPANY – STEAM HEAT PLANT | PINE GROVE | PA |
| PHOENIX UTILITY COMPANY – STEAM-OPERATED GENERATING PLANT | HAUTO | PA |
| PHOENIXVILLE HOSPITAL | PHOENIXVILLE | PA |
| PHOENIXVILLE INCINERATOR | PHOENIXVILLE | PA |
| Phoenixville Steel | Phoenixville | PA |
| PHYSICAL TEST LABS. | COATESVILLE | PA |
| PHYSICIANS AND DENTIST BUILDING | PHILADELPHIA | PA |
| PICKARD JOSEPH SONS CO | PHILADELPHIA | PA |
| PICKETT MIDDLE SCHOOL – WAYNE & CHELTEN | PHILADELPHIA | PA |
| PICKLES STEAK HOUSE | HORSHAM | PA |
| PICO Chemical | Clairton | PA |
| PICO Chemical | Chester | PA |
| PIERCE GLASS CO., THE | PORT ALLEGANY | PA |
| Pillsbury Plant | East Greenville | PA |
| PINE GROVE | PINE GROVE | PENNSYLVANIA |
| PINE KNOT COLLIERY | MINERSVILLE | PA |
| PINE RIDGE STIRLING BOILER HOUSE | HUDSON | PA |
| PINE TOWNSHIP COAL COMPANY | HEILWOOD | PA |
| Pipeline Service Co | Glenwillard | PA |
| PITT COM HEAT TREAT | PITTSBURGH | PA |
| PITT COMM HEAT TREATING | PITTSBURGH | PA |
| PITT STEEL FNDRY & MACHINE CO | MOKEESPORT | PA |
| PITT-FAB | PITTSBURGH | PA |
| Pittron | McKeesport | PA |
| PITTRON | GLASSPORT | PA |
| PITTRON A TEXTRON CO & MA | PITTSBURGH | PA |
| PITTRON A TEXTRON CO AND MA | GLASSPORT | PA |
| PITTS. COMM. HEATING | PITTSBURGH | PA |
| PITTSBUGH THERMAL LIMITED PARTNERSHIP | PITTSBURGH | PA |
| PITTSBURG COAL COMPANY | PITTSBURGH | PA |
| PITTSBURG COAL COMPANY | SCOTT HAVEN | PA |
| PITTSBURG COKE & CHEMICAL CO. | NEVILLE ISLAND | PA |
| PITTSBURG MCKEESPORT AND CONNELLSVILLE RAILROAD | PITTSBURGH | PA |
| PITTSBURG METAL PROCESS | SHARPSBURG | PA |
| PITTSBURG METALS PURIFYING PLANT – SAXONBURGH ROAD | SAXONBURG | PA |
| PITTSBURG PLATE GLASS COMPANY | PHILADELPHIA | PA |
| PITTSBURG PLATE GLASS COMPANY | PITTSBURGH | PA |
| PITTSBURG SHEAR KNIFE AND MACHINE COMPANY | PITTSBURGH | PA |
| Pittsburgh & Lake Erie Railroad | Beaver Falls | PA |
| PITTSBURGH & LAKE ERIE RAILROAD | MCKEES ROCK | PA |
| PITTSBURGH ACTIVATED CARBON CO – DEPT 144 – NEVILLE ISLAND | PITTSBURGH | PA |
| PITTSBURGH ACTIVATED CARBON CO – DEPT 3528 – NEVILLE ISLAND | PITTSBURGH | PA |
| PITTSBURGH ACTIVATED CARBON CO – DEPT 714 | NEVILLE ISLAND | PA |
| PITTSBURGH ACTIVATED CARBON CO – DEPT 848 – NEVILLE ISLAND | PITTSBURGH | PA |
| Pittsburgh Airport | Pittsburgh | PA |
| PITTSBURGH AND BIRMINGHAM TRACTION COMPANY | PITTSBURGH | PA |
| PITTSBURGH AND BIRMUNGHAM TRACTION COMPANY | PITTSBURGH | PA |
| PITTSBURGH AND BUTLER STREET RAILWAY COMPANY | RENFREW, BUTLER COUNTY | PA |
| PITTSBURGH AND BUTLER STREET RAILWAY COMPANY | RENFREW | PA |
| PITTSBURGH AND CONNEAUT DOCK COMPANY | PITTSBURGH | PA |
| PITTSBURGH AND LAKE ERIE RAILROAD | GLASSPORT | PA |
| PITTSBURGH AND LAKE ERIE RAILROAD COMPANY | PITTSBURGH | PA |
| PITTSBURGH AND WEST END PASSENGER RAILWAY COMPANY | PITTSBURGH | PA |
| PITTSBURGH AND WEST VIRGINIA RAILWAY COMPANY | ROOK | PA |
| PITTSBURGH ATHLETIC ASSOCIATION | PITTSBURGH | PA |
| PITTSBURGH ATHLETIC ASSOCIATION LAND COMPANY | PITTSBURGH | PA |
| PITTSBURGH BREWING CO | PITTSBURGH | PA |
| PITTSBURGH BREWING COMPANY | PITTSBURGH | PA |
| PITTSBURGH BUFFALO COMPANY | PITTSBURGH | PA |
| PITTSBURGH BUFFALO COMPANY | ELLSWORTH | PA |
| PITTSBURGH BUFFALO COMPANY | BURGETTSTOWN | PA |
| PITTSBURGH BUFFALO COMPANY | MARIANNA | PA |
| PITTSBURGH CITY FLOWER CO | GIBSONIA | PA |
| PITTSBURGH CITY HOME AND HOSPITAL AT MAYVIEW – POWER PLANT | PITTSBURGH | PA |
| PITTSBURGH COAL | PITTSBURGH | PA |
| PITTSBURGH COAL CO | ALLEGHENY | PA |
| PITTSBURGH COAL CO. SHOPS | LIBRARY | PA |
| PITTSBURGH COAL COMPANY | IMPERIAL | PA |
| PITTSBURGH COAL COMPANY | PITTSBURGH | PA |
| PITTSBURGH COAL COMPANY | GRINDSTONE | PA |
| Pittsburgh Coal Corporation | Imperial | PA |
| Pittsburgh Coal Corporation | Allegheny County | PA |
| Pittsburgh Coke & Chemical | Neville Island | PA |
| PITTSBURGH COKE & CHEMICAL CO. | NEVILLE ISLAND | PA |
| PITTSBURGH COKE & CHEMICAL CO. | MCKEES ROCKS | PA |
| PITTSBURGH COKE & CHEMICAL CO. – NEVILLE ISLAND | PITTSBURGH | PA |
| Pittsburgh Coke & Iron Company | Pittsburgh | PA |
| PITTSBURGH COMMERCIAL | PITTSBURGH | PA |
| PITTSBURGH CONSOLIDATION COAL CO. – R & D DIVISION | LIBRARY | PA |
| PITTSBURGH CONSOLIDATION COAL CO. – RESEARCH & DEVELOPMENT DIVISION | LIBRARY | PA |
| Pittsburgh Consolidation Coal Company – Montour 10 Mine – Pilot Plant Storeroom | Library | PA |
| Pittsburgh Consolidation Coal Company – Montour 10 Mine – RESEARCH & DEVELOPMENT DIVISION – PILOT PLANT STOREROOM | Library | PA |
| Pittsburgh Consolidation Coal Company – Montour 10 Mine – RESEARCH & DEVELOPMENT DIVISION – PILOT PLANT STOREROOM – LAB DIVISION | Library | PA |
| Pittsburgh Corning Corporation | Pittsburgh | PA |
| PITTSBURGH CORNING CORPORATION | PORT ALLEGANY | PA |
| Pittsburgh Corning Plant | Port Allegany | PA |
| PITTSBURGH COT FLOWER CO | GIDSONI | PA |
| PITTSBURGH CRANKSHAFT SERVICE | PITTSBUTGH | PA |
| Pittsburgh Crucible Steel | Midland | PA |
| PITTSBURGH CRUCIBLE STEEL COMPANY | MIDLAND | PA |
| PITTSBURGH CRUCIBLE STEL COMPANY | MIDLAND | PA |
| PITTSBURGH CUT FLOWER CO | GIBSONIA | PA |
| PITTSBURGH DES MOINES STEEL | PITTSBURGH | PA |
| PITTSBURGH DIE & CASTING CO | PITTSBURGH | PA |
| PITTSBURGH DIE & CASTING CO | SWISSVALE | PA |
| PITTSBURGH FERROMANGANESE COMPANY | CHESTER | PA |
| PITTSBURGH FLEXICORE CO I | MONONGAHELA | PA |
| PITTSBURGH FORGE AND IRON COMPANY | PITTSBURGH | PA |
| PITTSBURGH FORGE AND IRON COMPANY | ALLEGHENY | PA |
| PITTSBURGH FORGE AND IRON COMPANY | WOODS RUN | PA |
| PITTSBURGH FORGING | CORAOPOLIS | PA |
| PITTSBURGH FORGINGS CO | CORAPOLIS | PA |
| PITTSBURGH FORGINGS COMPANY | CORAOPOLIS | PA |
| PITTSBURGH GAGE & SUPPLY COMPANY | PITTSBURGH | PA |
| PITTSBURGH GAS AND COKE COMPANY – BY-PRODUCT WORKS | GLASSPORT | PA |
| PITTSBURGH GEAR CO | PITTSBURGH | PA |
| PITTSBURGH HARMONY BUTLER AND NEW CASTLE RAILWAY COMPANY | EVANS CITY | PA |
| PITTSBURGH HEAT | PITTSBURGH | PA |
| PITTSBURGH HOUSING AUTHORITY, TERRACE VILLAGE | PITTSBURGH | PA |
| PITTSBURGH INDUSTRIAL ENGR. CO. | PITTSBURGH | PA |
| PITTSBURGH IRON AND STEEL ENGINEERING COMPANY | PITTSBURGH | PA |
| PITTSBURGH KNIFE AND FORGE COMPANY | CORAOPOLIS | PA |
| PITTSBURGH LAKE ERIE RAILROAD COMPANY | MCKEES ROCKS | PA |
| PITTSBURGH LAKE ERIE RAILROAD DEPOT | PITTSBURGH | PA |
| PITTSBURGH MCKEESPORT AND WESTMORELAND RAILWAY COMPANY | MCKEESPORT | PA |
| PITTSBURGH MECHANICAL SYSTEMS INCORPORATED | PITTSBURGH | PA |
| PITTSBURGH METAL FABRICATING | PITTSBURGH | PA |
| PITTSBURGH METAL PROC. | PITTSBURGH | PA |
| PITTSBURGH METAL PROCESS | PITTSBURGH | PA |
| PITTSBURGH MILLING COMPANY | ALLEGHENY | PA |
| PITTSBURGH MILLING COMPANY | PITTSBURGH | PA |
| PITTSBURGH NATIONAL BANK – WOOD STREET | PITTSBURGH | PA |
| PITTSBURGH NIPPLE WORKS I | PITTSBURGH | PA |
| PITTSBURGH PLATE GLASS | TIPTON | PA |
| PITTSBURGH PLATE GLASS | SPRINGDALE | PA |
| PITTSBURGH PLATE GLASS | CREIGHTON | PA |
| PITTSBURGH PLATE GLASS | HARMARVILLE | PA |
| PITTSBURGH PLATE GLASS CO | PORT KENNEDY | PA |
| PITTSBURGH PLATE GLASS CO | FORD CITY | PA |
| PITTSBURGH PLATE GLASS CO – GLASS DIVISION – WORK NO 6 | FORD CITY | PA |
| PITTSBURGH PLATE GLASS CO – GLASS RESEARCH CENTER | HARMARVILLE | PA |
| PITTSBURGH PLATE GLASS CO – PAINT & BRUSH DIVISION | SPRINGDALE | PA |
| PITTSBURGH PLATE GLASS CO – WORKS 6 | FORD CITY | PA |
| Pittsburgh Plate Glass Company | Creighton | PA |
| Pittsburgh Plate Glass Company | Ford City | PA |
| PITTSBURGH PLATE GLASS COMPANY | ALLEGHENY | PA |
| PITTSBURGH PLATE GLASS COMPANY | NATRIUM | PA |
| PITTSBURGH PLATE GLASS COMPANY | TARENTUM | PA |
| PITTSBURGH PLATE GLASS COMPANY | CHARLEROI | PA |
| PITTSBURGH PLATE GLASS COMPANY | KENNERDELL | PA |
| PITTSBURGH PLATE GLASS COMPANY | PITTSBURGH | PA |
| PITTSBURGH PLATE GLASS COMPANY (PPG Industries) | Creighton | PA |
| Pittsburgh Plate Glass Industries | Harmarville | PA |
| PITTSBURGH POWERHOUSE | PITTSBURGH | PA |
| Pittsburgh Press | Pittsburgh | PA |
| PITTSBURGH PROVISION AND PACKING COMPANY | PITTSBURGH | PA |
| PITTSBURGH RAILWAYS | PITTSBURGH | PA |
| PITTSBURGH RAILWAYS COMPANY | BEAVER FALLS | PA |
| PITTSBURGH RAILWAYS COMPANY | PITTSBURGH | PA |
| PITTSBURGH RAILWAYS COMPANY, BRUNOTS’ ISLAND | PITTSBURGH | PA |
| PITTSBURGH REDUCTION COMPANY | NEW KENSINGTON | PA |
| PITTSBURGH REDUCTION COMPANY | PITTSBURGH | PA |
| Pittsburgh Rochester Coal | Indiana | PA |
| Pittsburgh Screw & Bolt Company | Pittsburgh | PA |
| PITTSBURGH SCREW AND BOLT COMPANY | MONACA | PA |
| PITTSBURGH SEAMLESS TUBE COMPANY | BEAVER FALLS | PA |
| PITTSBURGH STANDARD CONDUIT CO. | ETNA | PA |
| Pittsburgh Steamship Company | Pittsburgh | PA |
| Pittsburgh Steel | Midland | PA |
| Pittsburgh Steel | Allenport | PA |
| PITTSBURGH STEEL CASTING COMPANY | PITTSBURGH | PA |
| Pittsburgh Steel Co | Monesson | PA |
| PITTSBURGH STEEL CO | MONESSEN | PA |
| PITTSBURGH STEEL CO. | ALLENPORT | PA |
| PITTSBURGH STEEL CO. | MCKEES ROCKS | PA |
| Pittsburgh Steel Company | Allenport | PA |
| PITTSBURGH STEEL COMPANY | MONESSEN | PA |
| PITTSBURGH STEEL COMPANY | PITTSBURGH | PA |
| PITTSBURGH STEEL COMPANY | ALICIA | PA |
| Pittsburgh Steel Company – Allenport Plant | Allenport | PA |
| Pittsburgh Steel Company – Coke Plant | Monessen | PA |
| PITTSBURGH STEEL CORP | PITTSBURGH | PA |
| PITTSBURGH STEEL CORP (a/k/a Wheeling Pittsburgh Steel Co) | MONESSEN | PA |
| PITTSBURGH STEEL FOUNDRY | PITTSBURGH | PA |
| PITTSBURGH STEEL FOUNDRY | GLASSPORT | PA |
| PITTSBURGH STEEL FOUNDRY COMPANY | PITTSBURGH | PA |
| PITTSBURGH STEEL PRODUCTS COMPANY | ALLENPORT | PA |
| PITTSBURGH TERMINAL RAILROAD AND COAL COMPANY | HORNING | PA |
| PITTSBURGH TERMINAL WAREHOUSE AND TRANSFER COMPANY | PITTSBURGH | PA |
| Pittsburgh Theological Seminary | Pittsburgh | PA |
| PITTSBURGH THERMAL | PITTSBURGH | PA |
| PITTSBURGH TOOL STEEL WIRE | MONACA | PA |
| Pittsburgh Tube | Monaca | PA |
| PITTSBURGH VALVE AND FITTING COMPANY | PITTSBURGH | PA |
| PITTSBURGH WIRE COMPANY | PITTSBURGH | PA |
| PITTSBURGH WIRE COMPANY | BRADDOCK | PA |
| PITTSBURGH, CINCINNATI, CHICAGO AND ST. LOUIS RAILROAD | PITTSBURGH | PA |
| PITTSBURGH, CINCINNATI, CHICAGO AND ST. LOUIS RAILROAD | SCULLY | PA |
| PITTSBURGH, HARMONY, BUTLER AND NEW CASTLE RAILWAY COMPANY | HARMONY | PA |
| PITTSBURGH, MCKEESPORT AND CONNELLSVILLE RAILROAD | FARR STA. | PA |
| PITTSTON COAL MINING COMPANY | SUGAR NOTCH | PA |
| Plant Asbestos Company | Pittsburgh | PA |
| Plaza Apartments | Philadelphia | PA |
| PLUMB FAYETTE H INC | PHILADELPHIA | PA |
| PLUMB FAYETTE R INC | PHILADELPHIA | PA |
| PLUMB INC FAYETTE R | PHILADELPHIA | PA |
| PLYMOUTH COAL COMPANY | WILKES BARRE | PA |
| PLYMOUTH NUMBER 5 WASHERY | PLYMOUTH JUNCTION | PA |
| POCONA CREEK APARTMENTS | STROUDSBURG | PA |
| POINT BREEZE | PHILADELPHIA | PA |
| POINT BREEZE GAS WORKS | PHILADELPHIA | PA |
| POINT BREEZE REFINERY | PHILADELPHIA | PA |
| POINT MARION POWERHOUSE | POINT MARION | PA |
| POLLOCK SCHOOL – WELSH ROAD | PHILADELPHIA | PA |
| Polymer Corporation | Reading | PA |
| PONCE DE LEON | CHESTER | PA |
| POPE TIN PLATE COMPANY | PITTSBURGH | PA |
| Porcelain Products | Parkersburg | PA |
| PORTAGE COAL MINING COMPANY | PORTAGE | PA |
| Porter Building | Pittsburgh | PA |
| PORTER CO A K | PHILADELPHIA | PA |
| PORTER CO H K | PHILADELPHIA | PA |
| PORTER H K | PHILADELPHIA | PA |
| Portland Cement Co. | Allentown | PA |
| POST OFFICE – 30TH STREET | PHILADELPHIA | PA |
| Post Office 30th Street Station | Philadelphia | PA |
| POTERO JOHN V | PHILADELPHIA | PA |
| POTLACH PAPER MILL | LOCK HAVEN | PA |
| POTOMAC (USS) | CHESTER | PA |
| POTTER SONS AND COMPANY | PHILADELPHIA | PA |
| POTTSGROVE SCHOOL | POTTSTOWN | PA |
| Pottstown Hospital | Pottstown | PA |
| POTTSTOWN IRON COMPANY | POTTSTOWN | PA |
| POTTSVILLE AREA MIDDLE SCHOOL | POTTSVILLE | PA |
| Pottsville Hospital | Pottsville | PA |
| POTTSVILLE IRON AND STEEL COMPANY | POTTSVILLE | PA |
| POTTSVILLE WATER COMPANY – PUMPING STATION | POTTSVILLE | PA |
| POWELTON ELECTRIC COMPANY – LIGHT PLANT | PHILADELPHIA | PA |
| POWELTON GARDENS | PHILADELPHIA | PA |
| POWER ATOMIC POWER STATION | SHIPPINGPORT | PA |
| Power House | Butler | PA |
| POWER PIPING | DONORA | PA |
| POWER PIPING | PITTSBURGH | PA |
| Power Piping Company | Clairton | PA |
| POWER SYSTEMS OPERATIONS | EBENSBURG | PA |
| POWERHOUSE – SHIPPINGPORT | SHIPPINGPORT | PA |
| POWERS WEIGHTMAN ROSENGARTEN COMPANY | PHILADELPHIA | PA |
| Ppg | Ford City | PA |
| PPG | HARMARVILLE | PA |
| PPG | MEADVILLE | PA |
| PPG INDUSTIRES INC | MEADVILL | PA |
| PPG Industries | Carlisle | PA |
| PPG Industries | Pittsburgh | PA |
| PPG INDUSTRIES | MEADVILLE | PA |
| PPG INDUSTRIES / PITTSBURG PLATE GLASS | HARMARVILLE | PA |
| PPG INDUSTRIES INC | TIPTON | PA |
| PPG Industries, Inc. | Harmar Township | PA |
| PPL – BRUNNER ISLAND STEAM ELECTRIC STATION – UNIT 3 | YORK HAVEN | PA |
| PRECISION GRINDING COMPANY | PHILADELPHIA | PA |
| PRECISION GRINDING WHEEL | PHILADELPHIA | PA |
| PRECISION HEAT TREATMENT | SOUTHAMPTON | PA |
| PRECISION PRODUCTS COMPANY, BERRY RD. | WASHINGTON | PA |
| Presbyterian Church | Bradford | PA |
| PRESBYTERIAN HOME FOR WIDOWS AND SINGLE WOMEN | PHILADELPHIA | PA |
| PRESBYTERIAN HOSPITAL | PHILADELPHIA | PA |
| Prescotech | Erie | PA |
| Presque Isle Boiler | Erie | PA |
| Presque Isle Paper Co | Erie | PA |
| Pressed Steel Car Co | Pittsburgh | PA |
| Pressed Steel Car Company | Mckees Rocks | PA |
| PRESSED STEEL CAR COMPANY | ALLEGHENY | PA |
| PRESSED STEEL CAR COMPANY | PITTSBURGH | PA |
| PRESSURE PRODUCTS INDUSTRIES PLANT | HATBORO | PA |
| Prestolite Battery | Reading | PA |
| Price Battery Corp. | Hamburg | PA |
| PRICE H C & CO | PHILADELPHIA | PA |
| PRIDE | CHESTER | PA |
| PRIMROSE COLLIERY | MAHANOY CITY | PA |
| PRINCESS FURNACE COMPANY | GLEN WILTON | PA |
| PRISON – MEN’S HOUSE OF DETENTION | PHILADELPHIA | PA |
| PROCTER AND GAMBLE | TUNKHANNOCK | PA |
| PROCTER AND GAMBLE COMPANY | MEHOOPANY | PA |
| PROCTER AND GAMBLE PAPER PRODUCTS | MEHOOPANY | PA |
| Proctor & Swartz | Philadelphia | PA |
| PROCTOR AND SCHWARTZ INC | PHILADELPHIA | PA |
| PROCTOR ELLISON COMPANY | ELKLAND | PA |
| PROGRESS MANUFACTURING | PHILADELPHIA | PA |
| Progressive Manufacturing Company | Philadelphia | PA |
| PROJECTILE PLANT NUMBER 2 – ARMY GUN CARRIAGE SHOP | SOUTH BETHLEHEM | PA |
| PROSPECT COLLIERY | WILKES BARRE | PA |
| PROVIDENCE HOSPITAL | BEAVER FALLS | PA |
| Prudential Insurance Building | Upper Dublin | PA |
| PT. RICHMOND | PHILADELPHIA | PA |
| PTTISBURGH & WEST VIRGINIA RAILWAY CO | ROOK | PA |
| PUBLIC LEDGER BUILDING | PHILADELPHIA | PA |
| PUBLIC SCHOOL | PHILADELPHIA | PA |
| PUBLIC SERVICE CORPORATION OF NEW JERSEY | PHILADELPHIA | PA |
| Public Service Gas Co | Philadelphia | PA |
| PUBLICKER COMMERCIAL ALCOHOL COMPANY | CORNWELLS HEIGHTS | PA |
| PUBLICKER INDUSTRIES | SOUTH PHILADELPHIA | PA |
| PUBLICKER INDUSTRIES | PHILADELPHIA | PA |
| Publicker Industries, Distillers | Philadelphia | PA |
| PUBLICKER INDUSTRIES, INC. | PHILADELPHIA | PA |
| Publicker Industries, Inc. – Chemical Plant – Receiving Station 1 | Philadelphia | PA |
| PUBLICKERS DISTILLERY | PHILADELPHIA | PA |
| PULLMAN COMPANY | PULLMAN | PA |
| Pullman Standard Car Manufacturing Company | Butler | PA |
| Pumping Station-Landers Point | Landers Point | PA |
| PUNXSUTAWNEY ELEM. SCHOOL – PUNXSUTAWNEY SECONDARY SCHOOL | PUNXSUTAWNEY | PA |
| Punxsutawney Hardware | Punxsutawney | PA |
| PUNXSUTAWNEY IRON COMPANY | PUNXSUTAWNEY | PA |
| PUNXSUTAWNEY SECONDARY SCHOOL | PUNXSUTAWNEY | PA |
| PURCHASING DEPARTMENT – 3 GATEWAY CENTER | PITTSBURGH | PA |
| Pure Oil Company | Marcus Hook | PA |
| Purex Corporation | Bristol | PA |
| PUSEY AND JONES SHIPBUILDING COMPANY | WILMINGTON | PA |
| PYNE COLLY | TAYLOR | PA |
| Quaker Boiler Repairing Co. | Philadelphia | PA |
| Quaker Chemical Corp. | Conshohocken | PA |
| QUAKER CITY CHOCOLATE CO. | PHILADELPHIA | PA |
| QUAKER CITY DYE WORKS | PHILADELPHIA | PA |
| Quaker City Iron Works | Philadelphia | PA |
| Quaker City Rubber Co | Wissinoming | PA |
| QUAKER EXPORT PACKAGING COMPANY, INC. | PHILADELPHIA | PA |
| Quaker Oats | Shiremanstown | PA |
| Quaker Oats Co | Shiremanstown | PA |
| QUAKER OATS COMPANY | SHIREMANSTOWN | PA |
| Quaker State Machine Company | Willow Grove | PA |
| QUAKER STATE METALS CO | LANCASTER | PA |
| QUAKER STATE METALS INC – MANEHIM PIKE | LANCASTER | PA |
| Quaker State Oil & Refinery | Emlenton | PA |
| Quaker State Oil & Refinery | Farmers Vall | PA |
| QUAKER STATE OIL REFINING CO – MCKEAN PLANT | FARMERS VALLEY | PA |
| QUAKER STATE OIL REFINING CORPORATION | EMLENTON | PA |
| QUAKER STATE OIL REFINING CORPORATION | FARMERS VALLEY | PA |
| QUAKERTOWN BRICK | QUAKERTOWN | PA |
| QUAKERTOWN BRICK & TILE CO | QUAKERTOWN | PA |
| QUAKERTOWN BRICK TILE CO | QUAKERTOWN | PA |
| QUAKERTOWN BRICK/TILE CO | QUAKERTOWN | PA |
| QUAKERTOWN ELECTRIC DEPARTMENT | QUAKERTOWN | PA |
| QUAKERTOWN TRACTOR COMPANY | QUAKERTOWN | PA |
| QUEEN CITY CLEANERS | ALIQUIPPA | PA |
| QUICKWAY INC | PHILADELPHIA | PA |
| Quin-T Corp. | Erie | PA |
| QUINT CORPORATION | ERIE | PA |
| R & J Supply Co | Erie | PA |
| R & M Steel | Carnegie | PA |
| R A DUCKWORTH – P G H STEAMLINE | PHILADELPHIA | PA |
| R D Werner Company | Greenville | PA |
| R J Supply Co | Erie | PA |
| R L MILLER | ENOLA | PA |
| R O Werner Co | Greenville | PA |
| R. AND H. SIMON | EASTON | PA |
| R. C. A. TUBE DIV. – COLOR SLURRY IV | LANCASTER | PA |
| R. C. A. VICTOR | LANCASTER | PA |
| R. C. A. VICTOR – OFFICE BLDG. | LANCASTER | PA |
| R. C. A. VICTOR DIVISION | LANCASTER | PA |
| R. C. A. VICTOR DIVISION – BLDGS. #2, 2A & 2B | LANCASTER | PA |
| R. C. A. VICTOR DIVISION – BLDGS. 2, 2A & 2B | LANCASTER | PA |
| R. HECKSCHER AND SONS | SWEDELAND | PA |
| R. HECKSHER AND SONS | PHILADELPHIA | PA |
| R. HECKSHER AND SONS | SWEDELAND | PA |
| R. K. LAROS SILK COMPANY | BETHLEHEM | PA |
| R. SHAFER SUPT. | CORNWELLS HEIGHTS | PA |
| R.A. DUCKWORTH, P.G.H. STEAMLINE | PHILADELPHIA | PA |
| R.B. MURRAY OAKLAND ARCADE COMPANY | PITTSBURGH | PA |
| R.C. REMMEY DIVISION | PHILADELPHIA | PA |
| R.C.A. | Lancaster | PA |
| R.C.A. | Dunmore | PA |
| R.C.A. Building | Sayre | PA |
| R.D. ISAACS AND SON | WILKES BARRE | PA |
| R.D. WOOD | PHILADELPHIA | PA |
| R.D. WOOD BUILDING | PHILADELPHIA | PA |
| R.H. HICKMAN COMPANY | MCKEES ROCKS | PA |
| R.J. CAREY COMPANY | WILLIAMSPORT | PA |
| R.M. ARMSTRONG | WEST CHESTER | PA |
| R.R. SHOPS | MCKEES ROCKS | PA |
| RACQUET CLUB EAST APARTMENTS | LEVITTOWN | PA |
| Radiant Steel Products Company | Williamsport | PA |
| RADIO CORP OF AMERICA/RCA | LANCASTER | PA |
| RADIO CORPORATION OF AMERICA, TUBE DIVISION | LANCASTER | PA |
| RAILWAY SPEC. CORP | GROYDEN | PA |
| RAILWAY SPEC. CORPORATION | CROYDEN | PA |
| RAILWAY SPECIALTIES | BRISTOL | PA |
| RAILWAY SPRING AND MANUFACTURING COMPANY | PITTSBURGH | PA |
| RAILWAY STEEL SPRING COMPANY | LATROBE | PA |
| RAINEY WOOD COKE COMPANY | SWEDELAND | PA |
| Ramsey Hardware & Paneling Co | New Castle | PA |
| RANKIN US STEEL CARRIE FURNACE (HOMESTEAD WORKS) | RANKIN | PA |
| Rankin US Steel Carrie Furnace a/k/a Homestead Works | Rankin | PA |
| Ranson Hospital | Ranson | PA |
| RAUB SUPPLY | LANCASTER | PA |
| Raybestos Div. – Ray-Man. Inc. | Manheim | PA |
| Raybestos Manhattan | Mannheim | PA |
| RAYBESTOS MANHATTAN INC. | MANHEIM | PA |
| Raybestos Manhattan Plant | Manheim | PA |
| Raymark Company | Manheim | PA |
| RAYSTOWN WATER POWER COMPANY – HYDROELECTRIC PLANT | HUNTINGTON | PA |
| RCA | SCRANTON | PA |
| Rca Corporation. | Lancaster | PA |
| Rca Plant | Dunmore | PA |
| Rca Tube Division | Lancaster | PA |
| RCA Victor Division – Manufacturing Plant | Lancaster | PA |
| REACING RAILROAD CO | PHILADELPHIA | PA |
| READ AND LOVATT MANUFACTURING COMPANY | WEATHERBY | PA |
| READING CO | PHILADELPHIA | PA |
| READING HOSPITAL | WEST READING | PA |
| READING HOSPITAL | READING | PA |
| Reading Iron Co | Reading | PA |
| READING IRON COMPANY | READING | PA |
| READING IRON COMPANY | DANVILLE | PA |
| READING IRON COMPANY | EMAUS | PA |
| READING IRON COMPANY TUBE WORKS | READING | PA |
| READING IRON WORKS | READING | PA |
| Reading Metals Refining Co. | Reading | PA |
| Reading Railroad | Reading | PA |
| READING RAILROAD CO | PHILADELPHIA | PA |
| Reading Railroad Company | King Of Prussia | PA |
| READING RAILROAD SHOPS | NOT PROVIDED | PA |
| READING REHABILITATION HOSPITAL | READING | PA |
| READING SHALE BRICK COMPANY | READING | PA |
| READING TRANSPORT | READING | PA |
| READING TUBE CORP | READING | PA |
| Reading Tube Division | Reading | PA |
| READING WATER WORKS | READING | PA |
| READING WHITEHALL PAPERBOARD | READING | PA |
| REAL ESTATE TRUST BUILDING | PHILADELPHIA | PA |
| REAL ESTATE TRUST COMPANY | PHILADELPHIA | PA |
| Real Estate Trust Office Building | Philadelphia | PA |
| Red Lion High School | Red Lion | PA |
| RED LION PLANT – MANUFACTURING PLANT | PHILADELPHIA | PA |
| REDINGTON STANDARD FITTINGS COMPANY | REDINGTON | PA |
| REED ELECTRIC COMPANY – MANUFACTURING PLANT | PHILADELPHIA | PA |
| Reedsdale P.S. | Reedsdale | PA |
| Reedsville Power Station | Kittanning | PA |
| REESE METAL PRODUCTS CORP | LANCASTER | PA |
| Refactory & Insulation Corp | Port Kennedy | PA |
| REFRACTORY & INSULATION CORP | PORT KENNEDY | PA |
| Refractory & Insulation Corp. | Port Kennedy | PA |
| Refractory Specialities Sales Co | Morristown | PA |
| REICHARD COULSTON | BETHLEHEM | PA |
| REICHARD COULSTON COMPANY | BETHLEHEM | PA |
| REICHARD-COULSTON INC. | PHILADELPHIA | PA |
| REIDER BROTHERS | PHILADELPHIA | PA |
| REINERS | PITTSBURGH | PA |
| REIRLAY STATE HOSPITAL | HEMLOCK CREEK | PA |
| REISINGER PRATHER COMPANY | PITTSBURGH | PA |
| RELIANCE CEMENT COMPANY | COPLAY | PA |
| RELIANCE COKE COMPANY | DENBEAU | PA |
| RELIANT ENERGY MID ATLANTIC | JOHNSTOWN | PA |
| RELIANT ENERGY WHOLESALE GROUP | NEW FLORENCE | PA |
| RELIANT ENERGY WHOLESALE GROUP | SHAWVILLE | PA |
| REMINGTON RAND | MONTGOMERY COUNTY | PA |
| REMMEY DIVISION | PHILADELPHIA | PA |
| REMMEY DONALD B WOOD PROD | SOUTHAMPTON | PA |
| Remmey Refractory | Philadelphia | PA |
| Remmy Division A P Green | Philadelphia | PA |
| RENNEPAMP SUPPLY COMPANY | PITTSBURGH | PA |
| RENOVO SHOPS | RENOVO | PA |
| Republic Heater Co | Erie | PA |
| REPUBLIC ALUMINUM | BEAVER FALLS | PA |
| REPUBLIC COKE WORKS | REPUBLIC, FAYETTE COUNTY | PA |
| REPUBLIC IRON AND STEEL COMPANY | PITTSBURGH | PA |
| REPUBLIC IRON AND STEEL COMPANY | NEW SALEM | PA |
| REPUBLIC IRON AND STEEL COMPANY | SHARON | PA |
| REPUBLIC IRON WORKS | PITTSBURGH | PA |
| REPUBLIC STEEL | NEW BRIGHTON | PA |
| REPUBLIC STEEL CORP | WEST NEWTON | PA |
| REPUBLIC STEEL CORP | W NEWTON | PA |
| REPUBLIC STEEL CORP. | BEAVER FALLS | PA |
| REPUBLIC STEEL CORPORATION | BEAVER FALLS | PA |
| RESEARCH & DEVELOPMENT CENTER – BLDG #11 | LANCASTER | PA |
| RESEARCH & DEVELOPMENT CENTER – BLDG #12 | LANCASTER | PA |
| RESEARCH & DEVELOPMENT CENTER – BLDG #4 | LANCASTER | PA |
| RESEARCH & DEVELOPMENT CENTER – BLDG #5 | LANCASTER | PA |
| RESEARCH & DEVELOPMENT CENTER – FIRE TEST ROOM | LANCASTER | PA |
| RESEARCH & DEVELOPMENT CENTER – SOUTH END BLDG 4 – 2ND FLR ADD | LANCASTER | PA |
| RETREAT STATE HOSPITAL | HUNLOCK CREEK | PA |
| Revonah Yarn Mills | Hanover | PA |
| REYNOLD MACHINE | MIDVALE | PA |
| Reynolds Manufacturing Company | Avonmore | PA |
| REYNOLDS METALS ALUMINUM PLANT | CHESTER | PA |
| REYNOLDS METALS CO | CHESTER | PA |
| RFG 1 – RFD NBR 1 | PEN ARGYL | PA |
| RHODIA, INCORPORATED | MORRISVILLE | PA |
| RHONE POULENC RORER INCORPORATED | COLLEGEVILLE | PA |
| RICHARD FINISHING COMPANY, INCORPORATED | JERWYN | PA |
| RICHARD HECKSCHER AND SONS | SWEDELAND | PA |
| Richardson Paint Company | Philadelphia | PA |
| Richmond Power Plant | Philadelphia | PA |
| RICHMOND WORKS | PHILADELPHIA | PA |
| RICH-SAMPLINER KNITTING MILLS COMPANY | CONSHOHOCKEN | PA |
| RICO REALTY COMPANY | PHILADELPHIA | PA |
| Riddle Memorial Hospital | Media | PA |
| RIDGE EQUIPMENT CO | FALLEN TIMBER | PA |
| RIECK MCJUNKIN DAIRY COMPANY | PITTSBURGH | PA |
| Riggs Distiller & Co | Lancaster | PA |
| Riggs Distler (Phila. Navy Yard) | Philadelphia | PA |
| Riley Stoker | Cornwell Heights | PA |
| RILEY STOKER CORPORATION, 28TH & CHRISTIAN | PHILADELPHIA | PA |
| RIMERSBURG JR. HIGH SCHOOL | RIMERSBURG | PA |
| RIMERSBURG JR.-HIGH SCHOOL | RIMERSBURG | PA |
| RITER CONLEY MANUFACTURING COMPANY | PITTSBURGH | PA |
| Rittenhouse Apartments | Philadelphia | PA |
| RITTENHOUSE C & SON | QUAKERTOWN | PA |
| RITTENHOUSE PLAZA | PHILADELPHIA | PA |
| RITTMAN PROCESS CORPORATION | PITTSBURGH | PA |
| RITZ CARLTON HOTEL | PHILADELPHIA | PA |
| RIVER TOAD | MCKEES ROCKS | PA |
| Riverview Home for the Aged | Philadelphia | PA |
| Roadway Express | Harrisburg | PA |
| Roadway Express | Camp Hill | PA |
| Roaring Springs Paper Mill | Hollidaysburg | PA |
| ROBERT H. FOERDERER | PHILADELPHIA | PA |
| ROBERT PACKER HOSPITAL | SAYRE | PA |
| ROBERT PACKER HOSPITAL – BOILER ROOM | SAYRE | PA |
| ROBERT S MCQUEEN | PHILADELPHIA | PA |
| ROBERT S. MACQUEEN | PHILADELPHIA | PA |
| ROBERT SMITH ALE BREWING COMPANY | PHILADELPHIA | PA |
| ROBERT WOOLER COMPANY | DRESHER | PA |
| Robertson Fuel Oil | Linwood | PA |
| ROBERTSON-AMERICAN CORP A | MORRISVILLE | PA |
| ROBESONIA IRON COMPANY | ROBESON | PA |
| ROBESONIA IRON COMPANY | ROBESONIA | PA |
| ROBESONIA IRON COMPANY, LIMITED | ROBESONIA | PA |
| ROBESONIA IRON COMPANY, LIMITED | ROBESONIA, BERKS COUNTY | PA |
| ROBINDALE | NEAR SEWARD | PA |
| ROBINSON AND REA MANUFACTURING COMPANY | PITTSBURGH | PA |
| ROBINSON AND WALLACE | PHILADELPHIA | PA |
| ROBINSON CLAY PRODUCTS | POTTSTOWN | PA |
| ROBINSON CLAY PRODUCTS COMPANY | POTTSTOWN | PA |
| Robinson Protected Metal Co. – Ceiling | Pittsburgh | PA |
| Robinson Ventilating Company | Zelienople | PA |
| ROCH PITTSBURGHH COAL | HOMER CITY | PA |
| ROCHESTER & PITTSBURGH COAL | INDIANA COUNTY | PA |
| ROCHESTER & PITTSBURGH COAL CO. – LUCERNE POWER PLANT | LUCERNEMINES | PA |
| Rochester & Pittsburgh Coal Company | Lucerne Mines | PA |
| ROCHESTER AND PITTSBURGH COAL AND IRON COMPANY | PUNXSUTAWNEY | PA |
| ROCHESTER AND PITTSBURGH COAL AND IRON COMPANY | LUCERNE | PA |
| ROCHESTER AND PITTSBURGH COAL AND IRON COMPANY | HELVETIA | PA |
| ROCHESTER AND PITTSBURGH COAL AND IRON COMPANY | FALLS CREEK | PA |
| ROCHESTER AND PITTSBURGH COAL AND IRON COMPANY | DUBOIS | PA |
| ROCHESTER AND PITTSBURGH COAL AND IRON COMPANY | ELEANOR SHAFT MINE | PA |
| ROCHESTER AND PITTSBURGH COAL COMPANY | LUCERNE | PA |
| ROCHESTER GENERAL HOSPITAL | ROCHESTER | PA |
| Rochez Brothers & Supply Company | Braddock | PA |
| ROCK TENN COMPANY | DELAWARE WATER GAP | PA |
| ROCKHILL IRON AND COAL COMPANY | ROBERTSDALE | PA |
| ROCKHILL IRON AND COAL COMPANY | ORBISONIA | PA |
| ROCKPOINT SAND COMPANY OF PITTSBURGH | WEST ELLWOOD JUNCTION | PA |
| ROCKWELL INDUSTRIES | READING | PA |
| ROCKWELL INTERNATIONAL | NEW CASTLE | PA |
| Roebling Steel | Levittown | PA |
| Rohm & Haas | Bristol | PA |
| Rohm & Haas | Philadelphia | PA |
| Rohm & Haas | Bridesburg | PA |
| Rohm & Haas Chem Corp. | Bridesburg | PA |
| Rohm & Haas Chem Corp. | Philadelphia | PA |
| ROHM & HAAS CHEMICAL | BRIDESBURG | PA |
| ROHM & HAAS CHEMICAL | BRISTOL | PA |
| ROHM & HAAS CHEMICAL | PHILADELPHIA | PA |
| ROHM & HAAS CHEMICAL | SPRING HOUSE | PA |
| ROHM & HAAS CHEMICAL CO. | PHILADELPHIA | PA |
| ROHM & HAAS CO | PHILADELPHIA | PA |
| ROHM & HAAS CO. | BRIDGESBURG | PA |
| Rohm & Haas Company | Bristol | PA |
| ROHM & HAAS COMPANY | BRIDESBURG, PHILADELPHIA | PA |
| ROHM & HAAS COMPANY | PHILADELPHIA | PA |
| ROHM & HAAS COMPANY – BUILDING 36 – 5000 RICHMOND STREET | PHILADELPHIA | PA |
| ROHM & HAAS COMPANY, BUILDING 36, 5000 RICHMOND ST. | PHILADELPHIA | PA |
| Rohm & Hass | Bristol | PA |
| ROHM AND HAAS CO | PHILADELPHIA | PA |
| ROHM AND HAAS CO | BRISTOL | PA |
| ROHM AND HAAS COMPANY | BRISTOL | PA |
| ROHM AND HAAS COMPANY – MANUFACTURING PLANT | PHILADELPHIA | PA |
| ROHM AND HAAS COMPANY, WEST WASHINGTON SQUARE | PHILADELPHIA | PA |
| ROHM AND HAAS COMPANY, WEST WASHINGTON SQUARE | BRISTOL | PA |
| ROHM AND HAAS PLANT | BRISTOL | PA |
| ROHM ANTL BAAS CO | PHILADELPHIA | PA |
| Rojac Industries | Pittsburgh | PA |
| ROLLE MANF CO | LANSDALE | PA |
| ROMAN CATHOLIC PROTECTORY MONTGOMERY COUNTY | FLATLANDS | PA |
| ROOSEVELT HOTEL | PITTSBURGH | PA |
| RORBOROUGH CHESTNUT HILL AND MORRISTOWN RAILWAY COMPANY | PHILADELPHIA | PA |
| RORER GROUP, INCORPORATED | MONTGOMERY COUNTY | PA |
| Rosedale Foundry & Machine Company | Pittsburgh | PA |
| ROSEDALE FOUNDRY AND MACHINE COMPANY | PITTSBURGH | PA |
| ROSENA FURNACE | NEWCASTLE | PA |
| ROSSITER, MCGOVERN & COMPANY | PITTSBURGH | PA |
| ROTOBLAST | BUTLER | PA |
| ROUND HOUSE | SHARPSBURG | PA |
| ROXBOROUGH CHESTNUT HILL AND MORRISTOWN RAILWAY COMPANY | SHAWMUT STATION | PA |
| ROXBOROUGH HOSPITAL – ROXBOROUGH STREET | PHILADELPHIA | PA |
| Roxborough Memorial Hospital | Philadelphia | PA |
| ROYAL SWAN INC (a/k/a General Ribbon Mills, Inc.) | CATASAUQUA | PA |
| ROZMAN | PITTSBURGH | PA |
| RUBEL | ERIE | PA |
| Russell Mill | Rochester | PA |
| RUSSIAN AMERICAN MANUFACTURING COMPANY | PITTSBURGH | PA |
| RUSSIAN AMERICAN MANUFACTURING COMPANY | PHILADELPHIA | PA |
| RUST BOILER COMPANY | MIDLAND | PA |
| RUST ENGINEERING CO | PITTSBURGH | PA |
| Rust Engineering Company | Pittsburgh | PA |
| RUST FURNACE CO | PITTSBURGH | PA |
| RUTH BENNETT PROJECT | CHESTER | PA |
| Ryder & Richmond Oil Company | Bradford | PA |
| Rymet Corporation | King Of Prussia | PA |
| S M S AUTOMOTIVE | PHILADELPHIA | PA |
| S. BERN OHIO COMPANY | ROUSEVILLE | PA |
| S. EWART AND COMPANY | PITTSBURGH | PA |
| S. FAITH AND COMPANY | PHILADELPHIA | PA |
| S. FAITH COMPANY | PHILADELPHIA | PA |
| S. JARVIS ADAMS COMPANY | MIDLAND | PA |
| S. LANCASTER CO SCH AUTHORITY – NEW SR HIGH SCHOOL | QUARRYVILLE | PA |
| S. MARGOLIS & CO. | PHILADELPHIA | PA |
| S. MORGAN SMITH COMPANY | YORK | PA |
| S. S. BERTZ & SONS, INC. | LANCASTER | PA |
| S. W. Grease & Oil | Bakestown | PA |
| S.F. WHITMAN | PHILADELPHIA | PA |
| S.F. WHITMAN SON | PHILADELPHIA | PA |
| S.J. SHIMER AND SONS | MILTON | PA |
| S.K.F. INDUSTRIES INC. | PHILADELPHIA | PA |
| S.S. ATLANTIC ENG. | CHESTER | PA |
| S.S. ATLANTIC NAVIGATOR | CHESTER | PA |
| S.S. EAST HILLS | CHESTER | PA |
| S.S. EKTOR | PHILADELPHIA | PA |
| S.S. ESSO JAMESTOWN | CHESTER | PA |
| S.S. GLOBE PROGRESS | PHILADELPHIA | PA |
| S.S. GULF HOLLANDER | PHILADELPHIA | PA |
| S.S. GULF LUBE | GIRARD POINT | PA |
| S.S. ILLAPEL | CHESTER | PA |
| S.S. LY KAION | PHILADELPHIA | PA |
| S.S. MARVIN – EAST LIBERTY | PITTSBURGH | PA |
| S.S. MARVIN BRANCH | PITTSBURGH | PA |
| S.S. MERCANTILE WAVE | CHESTER | PA |
| S.S. MIDLAND | PHILADELPHIA | PA |
| S.S. MOBIL AERO | CHESTER | PA |
| S.S. OLYMPIC | CHESTER | PA |
| S.S. OLYMPIC ROCK | PHILADELPHIA | PA |
| S.S. OLYMPIC ROCK | CHESTER | PA |
| S.S. OLYMPIC STORIN | CHESTER | PA |
| S.S. RICHFIELD | CHESTER | PA |
| S.S. ROBIN SHERWOOD | PHILADELPHIA | PA |
| S.S. SISTER KATINGO | CHESTER | PA |
| SABINS MANUFACTURING CO | VERSAILLES | PA |
| SABINS MANUFACTURING CO I | VERSAILLES | PA |
| SACHENMAIR | HOLMSBURG | PA |
| Sacred Heart Hospital | Allentown | PA |
| SACRED HEART HOSPITAL | NORRISTOWN | PA |
| SAFE HARBOR WATER POWER CORPORATION – SAFE HARBOR HYDROELECTRIC STATION | SAFE HARBOR | PA |
| Safety Armorite Conduit Co | West Pittsburg | PA |
| SAINT AGNES HOSPITAL | PHILADELPHIA | PA |
| SAINT IGNATIUS CHURCH | YARDLEY | PA |
| SAINT JOE`S LEAD | MONACCA | PA |
| SAINT JOSEPH`S SCHOOL | NORRISTOWN | PA |
| SAINT LUKES HOSPITAL | BETHLEHEM | PA |
| SALEM BROSIUS INC | CARNEGIE | PA |
| SALEM BROSIUS INC | PITTSBURGH | PA |
| Salem Park Townhomes | Mechanicsburg | PA |
| SALL GEO METALS CO | PHILADELPHIA | PA |
| SALT GEO METALS CO | PHILADELPHIA | PA |
| SAMARITAN HOSPITAL | PHILADELPHIA | PA |
| SAMUEL HAIGHT AND COMPANY | BRIDGEWATER | PA |
| SAN JUAN CEMENT COMPANY | VEGA ALTA | PA |
| SANDUSKY CEMENT COMPANY | YORK | PA |
| SANDUSKY FOUNDRY | WEST HAZELTON | PA |
| SANITARY MILK CO. | CURWENSVILLE | PA |
| Sans Corp. | Erie | PA |
| Satellite Alloy Corporation | Springdale | PA |
| SAUCON | SOUTH BETHLEHEM | PA |
| SAUQUOIT SILK COMPANY | SCRANTON | PA |
| SAVAGE ARMS CORPORATION | PHILADELPHIA | PA |
| SAVAGE ARMS CORPORATION | SHARON | PA |
| SAVOIA PROPERTY MANAGEMENT COMPANY | NORWOOD | PA |
| SAW HILL TUBULAR | SHARON | PA |
| SAXTON IRON COMPANY | SAXTON | PA |
| SAYRE ELECTRIC COMPANY – GENERATING STATION | SAYRE | PA |
| SAYRE, PA | SAYRE | PA |
| SCAN | CHESTER | PA |
| Schaaf Heating & Air Conditioning | Greenville | PA |
| Schaefer Brewery | Philadelphia | PA |
| SCHAEFFER BREWERY | FOGELSVILLE | PA |
| SCHEIE EYE HOSPITAL | PHILADELPHIA | PA |
| SCHENLEY DISTILLERS CORPORATION | SCHENLEY | PA |
| SCHICK INC. | LANCASTER | PA |
| SCHMIDT AND AULT PAPER COMPANY | YORK | PA |
| SCHMIDT LUMBER MILLWORK | SCRANTON | PA |
| SCHOEN PRESSED STEEL COMPANY | PITTSBURGH | PA |
| SCHOEN PRESSED STEEL COMPANY | ALLEGHENY CITY | PA |
| SCHOEN STEEL WHEEL COMPANY | MCKEES ROCKS | PA |
| SCHOEN STEEL WHEEL COMPANY | PITTSBURGH | PA |
| SCHOENECK FARMS INC. | NAZARETH | PA |
| SCHOOL | CHESTNUT HILL | PA |
| School District Of Philadelphia | Philadelphia | PA |
| SCHOOLEY COLLIERY | DUNMORE | PA |
| SCHOOT OPTICAL | DURYEA | PA |
| SCHROEDER BROS. | PITTSBURGH | PA |
| SCHUTTE & DOARTING CO | CORNWALL HEIGHTS | PA |
| SCHUTTE & KOERTING | CORNWELL HEIGHTS | PA |
| SCHUTTE & KOERTING COMPAN | CORNWELLS HEIGHTS | PA |
| SCHUTTE AND KOERTING | CORNWELLS HEIGHTS | PA |
| SCHUTTE AND KOERTING COMPANY | CORNWELLS, BUCKS COUNTY | PA |
| SCHUTTE AND KOERTING COMPANY | PHILADELPHIA | PA |
| SCHUTTE AND KOERTING COMPANY | CORNWELLS | PA |
| SCHUYKILL FORGE CO | CORNWELLS HEIGHTS | PA |
| SCHUYLKILL ARSENAL PROPERTY | PHILADELPHIA | PA |
| SCHUYLKILL FORGE | CORNWELL HEIGHTS | PA |
| SCHUYLKILL FORGE | CORNWELLS HEIGHTS | PA |
| SCHUYLKILL FORGE CO | CORNWALL HEIGHTS | PA |
| SCHUYLKILL FORGE CO | CORNWELL HEIGHTS | PA |
| SCHUYLKILL FORGE CO | PHILADELPHIA | PA |
| SCHUYLKILL PRODUCTS INC. | CRESSONA | PA |
| SCHUYLKILL RAILWAY COMPANY | GIRARDVILLE | PA |
| SCHUYLKILL VALLEY TRACTION COMPANY | PHILADELPHIA | PA |
| Schwenkfelder Church | Worcester | PA |
| SCOFIELD ENGINEERING COMPANY | PHILADELPHIA | PA |
| SCOFIELD, MASON AND COMPANY | PHILADELPHIA | PA |
| Scotland School For Vets | Scotland | PA |
| SCOTT COLLIERY | MT. CARMEL | PA |
| SCOTT FOAM | EDDYSTONE | PA |
| Scott Paper | Chester | PA |
| SCOTT PAPER – PAPER MACHINE NBR 13 | CHESTER | PA |
| SCOTT PAPER – PAPER MACHINE NBR 18 | CHESTER | PA |
| Scott Paper Co | Chester | PA |
| Scott Paper Company | Philadelphia | PA |
| Scott Paper Company | Chester | PA |
| SCOTT PAPER COMPANY | EDDYSTONE | PA |
| SCOTT PAPER COMPANY – FRONT & MARKET STREETS | CHESTER | PA |
| SCOTT PAPER COMPANY – RESEARCH & DEVELOPMENT CENTER | ESSINGTON | PA |
| SCOTT PAPER COMPANY, FRONT & MARKET STS. | CHESTER | PA |
| SCOTT PAPER COMPANY, RESEARCH & DEVELOPMENT CENTER | ESSINGTON | PA |
| SCOTT PAPER MILL | CHESTER | PA |
| SCOTTDALE FURNACE COMPANY | SCOTTDALE | PA |
| SCOTTDALE IRON AND STEEL COMPANY | SCOTTDALE | PA |
| Scottdale Machine Foundry & Construction Company | Scottdale | PA |
| SCOTTDALE WOOD PROD | SCOTTDALE | PA |
| SCOTTDALE WOOD PRODUCTS COMPANY | SCOTTDALE | PA |
| SCOTTISH RITE CATHEDRAL – HAMILTON STREET | ALLENTOWN | PA |
| SCRANTON ANTHRACITE BRIQUETTE COMPANY | SCRANTON | PA |
| SCRANTON ANTHRACITE BRIQUETTE COMPANY | DICKSON CITY | PA |
| SCRANTON AXLE AND SPRING COMPANY | SCRANTON | PA |
| SCRANTON BOLT AND NUT COMPANY | SCRANTON | PA |
| Scranton Electric Co | Scranton | PA |
| SCRANTON ELECTRIC COMPANY – NORTH WASHINGTON AVENUE POWER PLANT | SCRANTON | PA |
| SCRANTON ELECTRIC COMPANY – WEST PITTSTON POWER STATION | PITTSTON | PA |
| Scranton Electric Construction Company | Scranton | PA |
| SCRANTON GAS AND WATER COMPANY – WATER PLANT | SCRANTON | PA |
| SCRANTON HIGH SCHOOL | SCRANTON | PA |
| SCRANTON LACE COMPANY | SCRANTON | PA |
| SCRANTON LACE CURTAIN COMPANY | SCRANTON | PA |
| SCRANTON ORDINANCE DIVISION | SCRANTON | PA |
| SCRANTON RAILWAY COMPANY | SCRANTON | PA |
| SCRANTON TECHNICAL HIGH SCHOOL | SCRANTON | PA |
| SEABOARD CONTAINER CORPORATION | BRISTOL | PA |
| Seaboard Steel & Manganese | Temple | PA |
| SEABOARD STEEL AND MANGANESE CORPORATION | TEMPLE | PA |
| SEALTEST FOODS | PHILADELPHIA | PA |
| SEARS & ROEBUCK | PHILADELPHIA | PA |
| SEARS ROEBUCK & CO | LANCASTER | PA |
| Sears Roebuck Company | Allentown | PA |
| SEARS ROEBUCK STORE – LANCASTER PIKE | READING | PA |
| Sears, Roebuck & Company, 27 51st St. | Pittsburgh | PA |
| SEARS, ROEBUCK AND COMPANY | PHILADELPHIA | PA |
| SECOND NATIONAL BANK | PITTSBURGH | PA |
| SECOND WARD SCHOOL | LATROBE | PA |
| SECURITY INVESTMENT COMPANY | TRAFFORD CITY | PA |
| SELAS | DRESHER | PA |
| SELAS CORP OF AMERICA | DRESHER | PA |
| SELAS CORP. OF AMERICA | BETHLEHEM | PA |
| Selas Corporation Of America | Dresher | PA |
| SELDEN COMPANY | BRIDGEVILLE | PA |
| SELDEN COMPANY | WEST END, PITTSBURGH | PA |
| SELINSGROVE STATE SCHOOL | SELINGROVE | PA |
| SEMET-SOLVAY COMPANY | DUNBAR | PA |
| SEMET-SOLVAY COMPANY, CAMBRIA STEEL COMPANY | JOHNSTOWN | PA |
| SEMET-SOLVAY COMPANY, CAUBRIA STEEL COMPANY | JOHNSTOWN | PA |
| SENCIT HOUSE | SHILLINGTON | PA |
| SENECA COLLIERY | PITTSTON JUNCTION | PA |
| SENIOR HIGH SCHOOL BUILDING | PHILADELPHIA | PA |
| SEPTA | Philadelphia | PA |
| Septa Powerhouse | Philadelphia | PA |
| SEWARD | SEWARD | PENNSYLVANIA |
| SEWARD POWER PLANT | JOHNSTOWN | PA |
| Seward Power Station | Seward | PA |
| Seward Public School | Seward | PA |
| SEWICKLEY ACADEMY | SEWICKLEY | PA |
| SEWICKLEY VALLEY HOSPITAL | SEWICKLEY | PA |
| SFK Industries, Inc. | Philadelphia | PA |
| SFK Industries, Inc. | Sunnytown Pike | PA |
| SGL ARBRASIVES | CARLISLE | PA |
| Shady Grove School | Montgomery County | PA |
| SHAFT 2 | IRWIN | PA |
| SHALLCROSS SCHOOL – BYBERRY & WOODHAVEN ROADS | PHILADELPHIA | PA |
| SHALLCROSS SCHOOL – BYBERRY ROAD | PHILADELPHIA | PA |
| SHAMOKIN AND COAL TOWNSHIP LIGHT, HEAT AND POWER COMPANY | SHAMOKIN | PA |
| Shamokin Dam | Selinsgrove | PA |
| SHAMOKIN LIGHT HEAT AND POWER COMPANY | SHAMOKIN | PA |
| SHAMOKIN LIGHT HEAT AND POWER COMPANY | SHARNOKIN | PA |
| SHARON COKE COMPANY | RONCO | PA |
| SHARON COKE COMPANY | MASONTOWN | PA |
| SHARON COKE COMPANY | PITTSBURGH | PA |
| SHARON COKE COMPANY | SHARON | PA |
| SHARON IRON COMPANY | SHARON | PA |
| Sharon Steel | FARRELL | PA |
| Sharon Steel | SHARON | PA |
| SHARON STEEL – FARRELL WORKS – OXYGEN PLANT | FARRELL | PA |
| Sharon Steel Co | Sharon | PA |
| Sharon Steel Co. | Farell | PA |
| Sharon Steel Co. | Sharon | PA |
| Sharon Steel Company | Sharon | PA |
| Sharon Steel Corp. | Farrell | PA |
| Sharon Steel Corporation | Farrell | PA |
| SHARON STEEL HOOP COMPANY | SHARON | PA |
| SHARON STEEL HOOP COMPANY | PITTSBURGH | PA |
| Sharon Tube | Sharon | PA |
| SHARON TUBE COMPANY | SHARON | PA |
| SHARON WATER WORKS COMPANY – WATER PLANT | SHARON | PA |
| SHARPLESS AND SONS | PHILADELPHIA | PA |
| SHARPSVILLE FURNACE COMPANY | SHARPSVILLE | PA |
| SHAWMONT SCHOOL – SHAWMONT AVENUE | PHILADELPHIA | PA |
| Shawville Power Station | Clearfield | PA |
| SHAWVILLE POWERHOUSE | CLEARFIELD | PA |
| SHELBE AND FISHER, FAIRMOUNT FORK WORKS | PHILADELPHIA | PA |
| SHELBY STEEL TUBE COMPANY | GREENVILLE | PA |
| SHELBY STEEL TUBE COMPANY | ELLWOOD CITY | PA |
| SHELBY STEEL TUBE COMPANY | PITTSBURGH | PA |
| SHELLY BROTHERS INC. | LANSDALE | PA |
| Shelocta Power Station | Shelocta | PA |
| Shenago Steel | Pittsburgh | PA |
| SHENANDOAH | CHESTER | PA |
| SHENANGO CHINA COMPANY | NEW CASTLE | PA |
| SHENANGO FURNACE COMPANY | SHARPSVILLE | PA |
| SHENANGO FURNACE COMPANY | WILPEN | PA |
| SHENANGO FURNACE COMPANY | WILMEN | PA |
| SHENANGO INC. | PITTSBURGH | PA |
| Shenango Inc. (a/k/a Davison Coke & Iron; Pittsburgh Coke & Iron) | Pittsburgh | PA |
| SHENANGO POTTERY COMPANY | NEWCASTLE | PA |
| Shenango Steel | Wheatland | PA |
| Shenango Steel | Neville Island | PA |
| Shenango Steel | Sharpsville | PA |
| SHENANGO VALLEY STEEL COMPANY | NEW CASTLE | PA |
| SHENANGO VALLEY WATER CO | SHARON | PA |
| Shenango Valley Water Company | Sharon | PA |
| SHENANGO VALLEY WATER COMPANY – WATER PLANT | SHARON | PA |
| SHENANGO, INCORPORATED | PITTSBURGH | PA |
| SHENANGO, INCORPORATED | SHARPSVILLE | PA |
| SHERATON INN WEST – THORN RUN ROAD | PITTSBURGH | PA |
| SHERATON MOTOR INN NORTH – MCKNIGHT ROAD | PITTSBURGH | PA |
| SHERIDAN SUPPLY COMPANY | NEWMANSTOWN | PA |
| Sherwin Hotel | Pittsburgh | PA |
| Sherwood Refining Co., Inc. | Warren | PA |
| SHERWOOD REFINING COMPANY | WARREN | PA |
| SHERWOOD SCHOOL | FOREST PARK | PA |
| SHIPMAN COAL COMPANY | SHAMOKIN | PA |
| SHIPMAN KOAL COMPANY | SHAMOKIN | PA |
| SHIPPENSBURG STATE COLLEGE – SCIENCE BUILDING | SHIPPENSBURG | PA |
| SHIPPING ATOMIC POWER STATION | MCKEES ROCKS | PA |
| SHIPPINGPORT ATOMIC POWER STATION | SHIPPINGPORT | PA |
| Shippingport Atomic Power Station, Beaver Valley | Shippingport | PA |
| Shippingport Nuclear Power Station | Shippingport | PA |
| SHIPPINGSPORT POWERHOUSE – ATOMIC PLANT | SHIPPINGSPORT | PA |
| SHIPYARD PHILADELPHIA | PHILADELPHIA | PA |
| SHOENBERGER STEEL COMPANY | PITTSBURGH | PA |
| SHOENBERGER WORKS | PITTSBURGH | PA |
| SHOOK ANDERSON MANUFACTURING COMPANY | PITTSBURGH | PA |
| SHOSHONE (USS) | CHESTER | PA |
| Shryock Radio Co. – Penn. A.C. Building | Philadelphia | PA |
| SHUANBERGER STEEL COMPANY | PITTSBURGH | PA |
| Shwartz Paper Mill | Philadelphia | PA |
| SID HARVEY OF PA | KING OF PRUSSIA | PA |
| SID HARVEY OF READING | ALLENTOWN | PA |
| SID HARVEY OF READING | READING | PA |
| Silk Mill | Dorranceton | PA |
| SILVER BROOK COAL COMPANY | SILVER BROOK | PA |
| SILVER BROOK COAL COMPANY | MAUCH CHUNK | PA |
| SILVER STEEL CORP | BETTENDORF | PA |
| Simon Gratz High School | Philadelphia | PA |
| SIMONDS ABRASIVE | PHILADELPHIA | PA |
| SIMONDS ABRASIVES CO | PHILADELPHIA | PA |
| SIMONIANS C F AND SONS | PHILADELPHIA | PA |
| SIMONIM OIL COMPANY | PHILADELPHIA | PA |
| SIMONIN OIL CO | PHILADELPHIA | PA |
| SIMPSON AND WATKINS | SCRANTON | PA |
| SIMPSON AND WATKINS | SERANTON | PA |
| SIMPSON AND WATKINS | BENNETT | PA |
| SIMPSON AND WATKINS | CARBONDALE | PA |
| SIMPSON AND WATKINS | COXTON | PA |
| SIMPSON AND WATKINS | DURYZA | PA |
| SIMPSON AND WATKINS | MAYFIELD | PA |
| SIMPSON AND WATKINS | PECKVILLE | PA |
| SIMPSON AND WATKINS | WYOMING | PA |
| SINCLAIR KOPPERS CO – KOBUTA PLANT | KOBUTA | PA |
| SINCLAIR KOPPERS CO – KOBUTA PLANT | MONACA | PA |
| SINCLAIR KOPPERS CO – MONOMER PLANT | KOBUTA | PA |
| SINCLAIR KOPPERS COMPANY – MONOMER PLANT | KOBUTA | PA |
| SINCLAIR OIL (BP) – TRAINER REFINERY | MARCUS HOOK | PA |
| SINCLAIR OIL REFINERY | TRAINOR | PA |
| SINCLAIR REFINING CO | TRAINER CHESTER | PA |
| Sinclair Refining Company | Marcus Hook | PA |
| SINCLAIR REFINING COMPANY | PHILADELPHIA | PA |
| Sinclair Refining Company (a/k/a BP Oil) | Marcus Hook | PA |
| SINGER ICE COMPANY | MCKEES ROCKS | PA |
| SINGER-NIMICK WORKS | PITTSBURGH | PA |
| Sinking Spring Foundry Co | Sinking Spring | PA |
| SISTERS OF GOOD SHEPHERD | PHILADELPHIA | PA |
| SISTERS OF MERCY BLDG B – MISERACORDIA COLLEGE | DALLAS | PA |
| SISTERS OF THE GOOD SHEPHERD | PHILADELPHIA | PA |
| SISTERS OF THE GOOD SHEPHERD | SCRANTON | PA |
| SITKIN METAL | LEWISTON | PA |
| SITKIN METAL TRADING, INC. | LEWISTOWN | PA |
| SKATING RINK | BETHLEHEM | PA |
| SKF – Altoona Plant – Addition | Altoona | PA |
| SKF Ball Bearing | Philadelphia | PA |
| SKF BALL BEARING – FRONT & ERIE STREETS | PHILADELPHIA | PA |
| SKF Industries | Philadelphia | PA |
| SKIN & CANCER CLINC | MCKEES ROCKS | PA |
| SKIN & CANCER CLINIC | MCKEES ROCKS | PA |
| SKINNER ENGINE COMPANY | ERIE | PA |
| SLATINGTON FOUNDRY, MACH AND BOILER WORKS | SLATINGTON | PA |
| SLOFEE MINE | PORTAGE | PA |
| Smith Brothers Iron Works | Philadelphia | PA |
| SMITH KLINE & FRENCH | CONSHOHOCKEN | PA |
| SMITH KLINE & FRENCH | PHILADELPHIA | PA |
| SMITH KLINE & FRENCH | SWEDESBORO | PA |
| SMITH KLINE & FRENCH | SWEDELAND | PA |
| SMITH KLINE & FRENCH | UPPER MARION | PA |
| Smith Kline & French, Beckman | Philadelphia | PA |
| SMITHFIELD ST. TERMINAL | PITTSBURGH | PA |
| SMOKETOWN ELEMENTARY SCHOOL – EAST LAMPETER TOWNSHIP | LANCASTER | PA |
| Snellenburg Building | Philadelphia | PA |
| SNYDER – LOCATION | MIDDLEBURG | PENNSYLVANIA |
| SOCIAL SECURITY BUILDING – 8TH & ARCH STREETS | PHILADELPHIA | PA |
| Socony Vacuum Oil Company | McCrae | PA |
| Solesbury Elementary School | Solesbury | PA |
| SOLIS-COHEN | PHILADELPHIA | PA |
| SOMERSET COAL COMPANY | BOSWELL | PA |
| SOMERSET HOSPITAL | SOMERSET | PA |
| Somerset Mills | Philadelphia | PA |
| SOMERSET SMOKELESS COAL COMPANY | BOSWELL | PA |
| Somerville Hospital | Somerville | PA |
| SONMAN SHAFT COAL COMPANY | PORTAGE | PA |
| SONNEBORN DIVISION | PETROLIA | PA |
| SONOCO PRODUCTS CO (a/k/a Downingtown Paper) | DOWNINGTOWN | PA |
| SORENSEN INDUSTRIES INC | DARRY | PA |
| Soult Wholesale Co | Clearfield | PA |
| SOUTH CHESTER TUBE COMPANY | CHESTER | PA |
| South Heights Power Station | Wireton | PA |
| SOUTH HILLS HIGH SCHOOL | PITTSBURGH | PA |
| SOUTH HILLS ICE COMPANY | DORMONT | PA |
| SOUTH MOUNTAIN JUNIOR HIGH SCHOOL | ALLENTOWN | PA |
| SOUTH PENN OIL COMPANY | ROUSEVILLE | PA |
| SOUTH PENN OIL COMPANY – PLANT NO 1 RECEIVING CLERK | ROUSEVILLE | PA |
| SOUTH PHILADELPHIA HIGH SCHOOL | PHILADELPHIA | PA |
| South Pittsburgh Water Company | Pittsburgh | PA |
| SOUTH PITTSBURGH WATER COMPANY – BECKS RUN PUMPING STATION | PITTSBURGH | PA |
| South Pittsburgh Water Company – E.H. Aldrich Treatment Complex | ELRAMA | PA |
| SOUTH PITTSBURGH WATER WO | PITTSBURGH | PA |
| SOUTH RIDE | PITTSBURGH | PA |
| SOUTH SIDE HOSPITAL | PITTSBURGH | PA |
| SOUTH WILKES BARRE COLLIERY | SOUTH WILKES BARRE | PA |
| Southeast Water Pollution Control Plant | PHILADELPHIA | PA |
| SOUTHERN CAMBRIA RAILWAY COMPANY | SOUTHFORK | PA |
| SOUTHERN CAMBRIA STREET RAILWAY COMPANY | JOHNSTOWN | PA |
| SOUTHERN CAMBRIA STREET RAILWAY COMPANY | SOUTH FORK | PA |
| SOUTHERN CROSS (T-AK-285) | CHESTER | PA |
| SOUTHERN KRAFT DIVISION INTERNATIONAL PAPER COMPANY | YORK HAVEN | PA |
| SOUTHERN MANUAL TRAINING SCHOOL | PHILADELPHIA | PA |
| Southern Natural Gas Company | Pittsburgh | PA |
| SOUTHERN NITROGEN CO | PORT WENTWORTH | PA |
| SOUTHERN TRACTION COMPANY | PITTSBURGH | PA |
| SOUTHMARK MILLS COMPANY | PHILADELPHIA | PA |
| SOUTHSIDE WORKS | PITTSBURGH | PA |
| SOUTHWARK FOUNDRY AND MACHINE COMPANY | PHILADELPHIA | PA |
| SOUTHWARK MILLS COMPANY | PHILADELPHIA | PA |
| SOUTHWARK POWER STATION | PHILADELPHIA | PA |
| SOUTHWEST WATER COMPANY – PUMPING STATION | CONNELLSVILLE | PA |
| Southwest Water Pollution Control Plant | PHILADELPHIA | PA |
| SPANG & CO. | BUTLER | PA |
| SPANG & CO. | PITTSBURGH | PA |
| SPANG CHALFANT & COMPANY, INCORPORATED | PITTSBURGH | PA |
| SPANG CHALFANT & COMPANY, INCORPORATED | SHARPSBURG | PA |
| SPANG STEEL AND IRON COMPANY | PITTSBURGH | PA |
| SPAUG CHALFAUT AND COMPANY | ETNA | PA |
| SPEARMAN IRON COMPANY | SHARPSVILLE | PA |
| SPECIALTY PRECISION WIRE | MT CARMEL | PA |
| SPECIALTY RINGS PRODUCTS | CORNWELLS HGTS | PA |
| SPECIATLY RINGS PRODUCTS | CORNWELLS HGTS | PA |
| Spector Freight System | Philadelphia | PA |
| SPECTRUM | PHILADELPHIA | PA |
| SPEER CARBON COMPANY | SAINT MARYS | PA |
| SPEER CARBON COMPANY – SPEER RESISTOR DIVISION | BRADFORD | PA |
| SPEER CARBON COMPANY, INCORPORATED | ST. MARYS | PA |
| Speer Carbon P I Bldg | St Marys | PA |
| SPEER RESISTOR DIVISION | BRADFORD | PA |
| SPICER MANUFACTURING COMPANY | POTTSTOWN | PA |
| SPIRAX-SARCO INCORPORATED | ALLENTOWN | PA |
| SPRECKELS SUGAR REFINERY | PHILADELPHIA | PA |
| SPRECKELS SUGAR REFINING COMPANY | PHILADELPHIA | PA |
| SPRENGER BREWING COMPANY | LANCASTER | PA |
| SPRING BROOK WATER SUPPLY COMPANY – WATER WORKS | SCRANTON | PA |
| SPRING FORD HIGH SCHOOL – SOUTH LEWIS ROAD | ROYERSFORD | PA |
| SPRING MILL MANOR | IVYLAND | PA |
| SPRINGDALE POWER STATION | SPRINGDALE | PA |
| Springdale Powerhouse | Springdale | PA |
| Spring-Ford Area High School | Royersford | PA |
| SPRINGS COTTON MILLS | LANCASTER | PA |
| SPRINGWELL FOUNDRY | CHESTER | PA |
| SS BERTZ WHSE | LANCASTER | PA |
| St Joe Mineral Corp. | Monaca | PA |
| St Joe Mineral Corp./aka St. Joe Lead | Monaca | PA |
| ST JOE MINERALS | JOSEPHTOWN | PA |
| ST JOE SMELTING | MONACA | PA |
| ST JOSEPH LEAD COMPANY 71 | MONACA | PA |
| ST LOUIS DIE CASTING CORP | RIPLEY | PA |
| ST LUKES HOSPITAL | BETHLEHEM | PA |
| ST. ANN SRC CHURCH | CASTLE SHANNON | PA |
| St. Bernard’s Church | Mt. Lebanon | PA |
| St. Bernard’s Roman Catholic Church | Pittsburgh | PA |
| St. Charles Seminary | Overbrook | PA |
| ST. CLAIR COAL COMPANY | ST. CLAIR | PA |
| ST. CORR INST AT HUNGTINDON | HUNTINGDON | PA |
| ST. ELIZABETH CONVENT | CORNWELLS | PA |
| ST. FRANCIS HOSPITAL | PITTSBURGH | PA |
| ST. FRANCIS RETREAT HOUSE – CHIPMAN ROAD | BETHLEHEM | PA |
| St. Hubert’s Convent | Philadelphia | PA |
| ST. JAMES ACTIVITY BUILDING | PITTSBURGH | PA |
| ST. JAMES EPISCOPAL CHURCH | LANCASTER | PA |
| St. Joe Lead | Johnstown | PA |
| St. Joe Lead | Monaca | PA |
| ST. JOE RESOURCES CO. | JOSEPHTOWN | PA |
| ST. JOE RESOURCES CO; CORPORATE RESEARCH CENTER | MONACA | PA |
| ST. JOHNS GENERAL HOSPITAL | PITTSBURGH | PA |
| ST. JOHN’S GENERAL HOSPITAL | PITTSBURGH | PA |
| ST. JOSEPH HOSPITAL | LANCASTER | PA |
| ST. JOSEPH LEAD COMPANY | JOSEPHTOWN | PA |
| ST. JOSEPH LEAD COMPANY | MONACA | PA |
| ST. JOSEPH LEAD COMPANY – JOSEPHTOWN SMELTER | JOSEPHTOWN | PA |
| ST. JOSEPH LEAD COMPANY – ZINC SMELTING DIVISION | JOSEPHTOWN | PA |
| ST. JOSEPH’S ACADEMY | GREENSBURG | PA |
| St. Joseph’s Hospital | Reading | PA |
| ST. JOSEPH’S HOSPITAL | LANCASTER | PA |
| ST. LOUIS PLATE GLASS COMPANY | PITTSBURGH | PA |
| ST. LUKE’S HOSPITAL | BETHLEHEM | PA |
| ST. LUKES HOSPITAL – FOUNTAIN HILL | BETHLEHEM | PA |
| ST. MARGARET HOSPITAL | PITTSBURGH | PA |
| ST. MARGARET’S HOSPITAL | PITTSBURGH | PA |
| St. Mark’s School | Altoona | PA |
| ST. MARY CATHOLIC CHURCH | CECIL | PA |
| ST. MARY HOSPITAL | PHILADELPHIA | PA |
| ST. MARY OF MERCY PARISH – STANWIX STREET | PITTSBURGH | PA |
| ST. MARY’S LAUNDRY | ARDMORE | PA |
| ST. MICHAEL THE ARCHANGEL CHURCH | BUTLER | PA |
| ST. NICHOLAS BUILDING | PITTSBURGH | PA |
| ST. PAUL’S CHURCH | PHILADELPHIA | PA |
| ST. PAUL’S ROMAN CATHOLIC ORPHAN ASYLUM | IDLEWOOD | PA |
| ST. PIUS X SEMINARY | DALTON | PA |
| ST. VINCENT HOSPITAL | ERIE | PA |
| Stackpole Carbon | St. Marys | PA |
| Stackpole Carbon Co. | St. Mary’s | PA |
| STACKPOLE CARBON CO. | ST MARY’S | PA |
| STAGMAIER BREWING CO | WILKES BARRE | PA |
| STALEY CORN SYRUP PLANT | MORRISVILLE | PA |
| STALEY STARCH | PHILADELPHIA | PA |
| STALEY SYRUPS | MORRISVILLE | PA |
| STANBRIDGE APARTMENTS | LANSDALE | PA |
| STANDARD CHAIR COMPANY | UNION CITY | PA |
| STANDARD FLOOR COMPANY | PITTSBURGH | PA |
| STANDARD ICE MANUFACTURING COMPANY | PHILADELPHIA | PA |
| STANDARD LIFE INSURANCE BLDING | PITTSBURGH | PA |
| STANDARD OIL | PHILADELPHIA | PA |
| STANDARD OIL | STEELTON | PA |
| STANDARD OIL COMPANY, ATLANTIC REFINERY | PHILADELPHIA | PA |
| STANDARD OIL TANK – HULL 601 | PHILADELPHIA | PA |
| STANDARD PRESS STEEL CO | JENKINTOWN | PA |
| Standard Press Steel Company | Jenkinstown | PA |
| STANDARD SANITARY MANUFACTURING COMPANY | NEW BRIGHTON | PA |
| STANDARD SCALE AND SUPPLY COMPANY | BEAVER FALLS | PA |
| STANDARD SEAMLESS LUBE COMPANY | ECONOMY | PA |
| Standard Seamless Tube Co | Economy | PA |
| STANDARD SEAMLESS TUBE COMPANY | ECONOMY | PA |
| Standard Steel | Burnham | PA |
| STANDARD STEEL | LEWISTON | PA |
| STANDARD STEEL CAR COMPANY | BUTLER | PA |
| STANDARD STEEL CAR COMPANY | PITTSBURGH | PA |
| STANDARD STEEL CAR COMPANY | RENFREW | PA |
| STANDARD STEEL COMPANY | BURNHAM | PA |
| STANDARD STEEL DIVISION, BALDWIN LIMA HAMILTON CORPORATION | BURNHAM | PA |
| STANDARD STEEL PLANT | BURNHAM | PA |
| STANDARD STEEL SPECIALTY | BEAVER FALLS | PA |
| STANDARD STEEL WORKS | BURNHAM | PA |
| STANDARD STEEL WORKS COMPANY | PHILADELPHIA | PA |
| STANDARD STEEL WORKS DIVISION | BURNHAM | PA |
| STANDARD STEEL, BALDWIN – LIMA – HAMILTON; DIV. OF TITANIUM METALS CORP. OF AMERICA | BURNHAM | PA |
| STANDARD TIN PLATE COMPANY | CANONSBURG | PA |
| STANDARD UNDERGROUND CABLE COMPANY | PITTSBURGH | PA |
| Stanley Electric | Altoona | PA |
| STANLEY G. FLAGG AND COMPANY | POTTSTOWN | PA |
| STANLEY SPRING WORKS | HARRISBURG | PA |
| STANLEY SPRING WORKS INC | HARRISBURG | PA |
| STANTON COLLIERY | ASHLEY | PA |
| STANZEL ALFRED | CRYODON | PA |
| STAR FIRE BRICK COMPANY | PITTSBURGH | PA |
| Starr Stores Warehouse | Philadelphia | PA |
| State Capital Building | Harrisburg | PA |
| State Correctional Institute | Camp Hill | PA |
| STATE CORRECTIONAL INSTITUTE | HOUTZDALE | PA |
| STATE CORRECTIONAL INSTITUTION | CAMP HILL | PA |
| State Hospital | Somerset | PA |
| STATE HOSPITAL FOR INSANE | NORRISTOWN | PA |
| State Institution | Polk | PA |
| STATE OFFICE BUILDING, COMMONWEALTH AVE. AND FOSTER ST. | HARRISBURG | PA |
| State Police Office – Capitol Building | Harrisburg | PA |
| STAUFFER C DAN | INGOMAR | PA |
| STAUFFER CHEMCIAL CO. | MORRISVILLE | PA |
| STAUFFER CHEMICAL | MORRISVILLE | PA |
| STAUFFER CHEMICAL CO | MORRISVILLE | PA |
| STAUFFER CHEMICAL COMPANY | MORRISVILLE | PA |
| STAUFFER CHEMICAL COMPANY | MARCUS HOOK | PA |
| STAUFFER CHEMICAL COMPANY, INCORPORATED | FRYE STATION | PA |
| STEAM GENERATING SERVICE | COATESVILLE | PA |
| STEAM GENERATOR SALES SERVICE | COATESVILLE | PA |
| STEEL CAR FORGE COMPANY | BUTLER | PA |
| STEEL CAR FORGE COMPANY | ELLWOOD CITY | PA |
| Steel City Lumber Co | Ambridge | PA |
| STEELE ELEMENTARY SCHOOL – WAYNE & BRISTOL | PHILADELPHIA | PA |
| STEELTON AND HIGHSPIRE RAIL ROAD COMPANY | BETHLEHEM | PA |
| Stefanak Company | Farrell | PA |
| STEGMAIER BREWING COMPANY | WILKES BARRE | PA |
| Stephen Girard Building | Philadelphia | PA |
| Sterling Land Company | Pittsburgh | PA |
| STERLING SILK GLOVE COMPANY | BANGOR | PA |
| STERN AND SILVERMAN | PHILADELPHIA | PA |
| STERN JACOB AND SONS | JENKINTOWN | PA |
| STERRICK CREEK COAL COMPANY | SCRANTON | PA |
| Stevenson Terrace Apartments | Philadelphia | PA |
| Stirling Sintering Company | South Heights | PA |
| Stone & Webster Engineering | Williamsport | PA |
| STONE CANYON CONSOLIDATED COAL COMPANY | WILKES BARRE | PA |
| STONE CONTAINER CORP | PHILADELPHIA | PA |
| Stone Container Corporation | Philadelphia | PA |
| STONE CONTAINER CORPORATION (a/k/a St. Regis Paper) | YORK | PA |
| STONER MUDGE COMPANY | PITTSBURGH | PA |
| STONER MUDGE COMPANY – ROCHESTER DIVISION | NORTH ROCHESTER | PA |
| STONER-MUDGE | ROCHESTER | PA |
| STORES DEPARTMENT | BEAVER FALLS | PA |
| Stouffer’s Plant | King Of Prussia | PA |
| STRAND TOWNSHIP – MONROE CO | EAST STROUDSBURG | PA |
| Stratton Motorcompany | Clearfield | PA |
| STRAUB BREWING | PITTSBURGH | PA |
| STRAWBERRY MANSION JUNIOR HIGH SCHOOL | PHILADELPHIA | PA |
| STRAWBRIDGE & CLOTHER DEPARTMENT STORE | GERMANTOWN PIKE | PA |
| STRAWBRIDGE & CLOTHIER | PHILADELPHIA | PA |
| STRAWBRIDGE & CLOTHIER – SW CORNER | SPRINGFIELD | PA |
| STRAWBRIDGE & CLOTHIER, SW COR | SPRINGFIELD | PA |
| STRICK TRAILERS | FAIRLESS HILLS | PA |
| Stricklands Hotel | Mt. Pocono | PA |
| Struthers and Wells | Titusville | PA |
| STRUTHERS COAL AND COKE COMPANY | NEW SALEM | PA |
| Struthers Scientific | Warren | PA |
| STRUTHERS STATION | WARREN | PA |
| STRUTHERS WELL CORP | WARREN | PA |
| STRUTHERS WELLS CORP | WARREN | PA |
| SUBURBAN GENERAL HOSPITAL | PITTSBURGH | PA |
| SUBURBAN PLANT – GENERATING STATION | SCRANTON | PA |
| Suburban Propane | Lancaster | PA |
| SUBURBAN STATION BUILDING | PHILADELPHIA | PA |
| SUBURBAN WATER COMPANY – PUMPING STATION | HULTON | PA |
| SUGAR APPARATUS MANUFACTURING COMPANY | PHILADELPHIA | PA |
| Sullifoam | Willow Grove | PA |
| Sullivan Products | Willow Grove | PA |
| SULZBERGER JUNIOR HIGH – 48TH & FAIRMONT AVENUE | PHILADELPHIA | PA |
| SUMMERDALE DYE & FIN INC | PHILADELPHIA | PA |
| SUMMERDALE DYEING & FINIS | PHILADELPHIA | PA |
| SUMMERDALE DYEING AND FINISH | PHILADELPHIA | PA |
| SUMMIT BRANCH MINING COMPANY | WILLIAMSTOWN | PA |
| SUMMIT BRANCH RAILROAD COMPANY | WILKES BARRE | PA |
| SUMMIT BRANCH RAILROAD COMPANY | WILLIAMSTOWN | PA |
| Summit Park Apartments | Philadelphia | PA |
| SUMPTER (USS) | PHILADELPHIA | PA |
| SUN COMPANY, INCORPORATED | PHILADELPHIA | PA |
| SUN COMPANY, INCORPORATED | OREGON | PA |
| SUN COMPANY, INCORPORATED, REFINERY | MARCUS HOOK | PA |
| Sun Oil | Chester | PA |
| Sun Oil | Marcus Hook | PA |
| SUN OIL | TOLEDO | PA |
| SUN OIL – MARCUS HOOK REFINERY | MARCUS HOOK | PA |
| Sun Oil Co | Marcus Hook | PA |
| Sun Oil Co | Twin Oaks | PA |
| SUN OIL CO. | TWIN OAKS | PA |
| SUN OIL CO. REFINERY | MARCUS HOOK | PA |
| Sun Oil Company | Marcus Hook | PA |
| SUN OIL COMPANY | PHILADELPHIA | PA |
| SUN OIL COMPANY | LINWOOD | PA |
| SUN OIL COMPANY | TWIN OAKS | PA |
| SUN OIL COMPANY – 17-13 AMONIA PLANT WAREHOUSE | MARCUS HOOK | PA |
| SUN OIL COMPANY – BLDG NBR 421 | MARCUS HOOK | PA |
| SUN OIL COMPANY – BUILDING 3 | TWIN OAKS | PA |
| SUN OIL COMPANY – COMMERCIAL CATALYTIC CRACKING PLANT | MARCUS HOOK | PA |
| SUN OIL COMPANY – FLARE TOWER | MARCUS HOOK | PA |
| SUN OIL COMPANY – Marcus Hook Refinery | MARCUS HOOK | PA |
| SUN OIL COMPANY – STORAGE TANK | MARCUS HOOK | PA |
| SUN OIL COMPANY – TWIN OAKS WAREHOUSE | TWIN OAKS | PA |
| SUN OIL COMPANY – TWIN OAKS WAREHOUSE – WAREHOUSE #3 | TWIN OAKS | PA |
| SUN OIL COMPANY WAREHOUSE | TWIN OAKS | PA |
| Sun Oil Plant | Marcus Hook | PA |
| Sun Petroleum | Marcus Hook | PA |
| SUN PETROLEUM COMPANY | MARCUS HOOK | PA |
| SUN REFINERY AND MARKETING | PHILADELPHIA | PA |
| Sun Refining & Marketing Co. | Philadelphia | PA |
| SUN SHIPBUILDING & DD CO. | CHESTER | PA |
| SUN SHIPBUILDING & DRY DOCK CO | CHESTER | PA |
| Sun Shipbuilding & Dry Dock Company, Sunship/Pennship | Chester | PA |
| Sun Shipbuilding & Drydock Co. | Chester | PA |
| SUN SHIPBUILDING AND DRYDOCK | EDDYSTONE | PA |
| SUN SHIPBUILDING AND DRYDOCK COMPANY | PHILADELPHIA | PA |
| SUN SHIPBUILDING AND DRYDOCK COMPANY | CHESTER | PA |
| SUN SHIPBUILDING COMPANY | CHESTER | PA |
| SUN TRANSPORT COMPANY | CHESTER | PA |
| Sunbeam Corporation | Meadville | PA |
| SUNBEAM EQUIPMENT CO | MEADVILLE | PA |
| SUNBEAM EQUIPMENT PLANT | MEADVILLE | PA |
| SUNBURY | SUNBURY | PENNSYLVANIA |
| SUNBURY AND NORTHUMBERLAND ELECTRIC RAILWAY – POWER PLANT | SUNBURY | PA |
| Sunbury Converting Works | Sunbury | PA |
| SUNOCO CHEMICAL, INCORPORATED | PHILADELPHIA | PA |
| SUNOCO REFINING AND MARKETING | MARCUS HOOK | PA |
| SUNOCO, INCORPORATED, (R&M) POINT BREEZE | PHILADELPHIA | PA |
| Sunship & Drydock Co. | Chester | PA |
| SUPERINTENDENT U.S. MINT | PHILADELPHIA | PA |
| Superior Boiler & Equipment Company | Ardmore | PA |
| Superior Builders Supply Co | Baden | PA |
| SUPERIOR COMBUSTION INDUSTRIES | EMMAUS | PA |
| SUPERIOR COMBUSTION, INC. | EMMAUS | PA |
| SUPERIOR DRAWN STEEL CO | MONACA | PA |
| Superior Lumber Co | Baden | PA |
| SUPERIOR STEEL | CARNEGIE | PA |
| SUPERIOR STEEL CORPORATION | CARNEGIE | PA |
| Superior Thread & Yarn Co | Philadelphia | PA |
| SUPERIOR ZINC CORP | BRISTOL | PA |
| Supplee Memorial Presbyterian Church | Maple Glen | PA |
| Supradur | Windgap | PA |
| Supradur Mfg. Corp. | Windgap | PA |
| SURFACE CHEMICALS INC – METALS DIVISION | FORBES ROAD | PA |
| SURFACE CHEMICALS INC – METALS DIVISION – NEAR GREENSBURG, PA. | FORBES ROAD | PA |
| Surface Combustion | Scranton | PA |
| Surpass Leather Co | Philadelphia | PA |
| SURPASS LEATHER COMPANY | PHILADELPHIA | PA |
| Susquehanna Coal Co. | Nanticoke | PA |
| SUSQUEHANNA COAL COMPANY | NANTICOKE | PA |
| SUSQUEHANNA COAL COMPANY | STEARNS | PA |
| SUSQUEHANNA COAL COMPANY | NEWPORT CENTRE (#4 SHAFT) | PA |
| SUSQUEHANNA COAL COMPANY | WILKES BARRE | PA |
| SUSQUEHANNA COLLIERIES COMPANY | MT. CARMEL | PA |
| Susquehanna Power Station | Shawville | PA |
| Susquehanna Power Station | Shawville Station | PA |
| Susquehanna Silk Mills | Huntington | PA |
| SUSQUEHANNA SILK MILLS | JERSEY SHORE | PA |
| SUSQUEHANNA SILK MILLS | SUNBURY | PA |
| SUSQUEHANNA UNIVERSITY – WOMENS & MENS DORMITORIES | SELINSGROVE | PA |
| Susquehannock High School | Glen Rock | PA |
| SUSQUE-VIEW HOME NURSING AND REHABILITATION CENTER | LOCK HAVEN | PA |
| SUSTEK PAUL CO INC | PHILLY | PA |
| SWEES STEEL COMPANY | WILLIAMSBURG | PA |
| Sweet’s Steel | Williamsport | PA |
| SWIFT AND COMPANY | CHAMBERSBURG | PA |
| Swindell Dressler Co. | Pittsburgh | PA |
| SWINDELL-DRESSLER COMPANY | PITTSBURGH | PA |
| SWING AND BATEMAN | PHILADELPHIA | PA |
| SYKESVILLE COKE COMPANY | SYKESVILLE, JEFFERSON COUNTY | PA |
| SYLVANIA ELEC PROD INC | YORK | PA |
| SYLVANIA ELEC PROD INC | WARREN | PA |
| SYLVANIA ELECTRIC PRODUCT | YORK | PA |
| SYLVANIA ELECTRIC PRODUCTS CO. – NEW MFG. BLDG. & BOILER HOUSE | WILLIAMSPORT | PA |
| Sylvania Electric Products, Inc. | Emporium | PA |
| Syntex Corporation | Allentown | PA |
| SYNTHANE CORP | OAKS | PA |
| SYNTHANE CORPORATION | OAKS | PA |
| SYNTHANE-TAYLOR CORP (a/k/a Taylor Fibre) | Norristown | PA |
| T.C. ROBERTS AND COMPANY | PHILADELPHIA | PA |
| TACONY IRON AND METAL COMPANY | TACONY | PA |
| TACONY ORDNANCE CORPORATION | TACONY | PA |
| TALCO METAL PRODUCTS COMPANY | PHILADELPHIA | PA |
| TALCO METALS COMPANY | PHILADELPHIA | PA |
| Tapper Supply Company | Hazleton | PA |
| TARENTUM BOROUGH | TARENTUM | PA |
| TARENTUM LIGHT AND WATER PLANT | TARENTUM | PA |
| TARENTUM PAPER MILLS | TARENTUM | PA |
| Tarinto Monument Works | Lehigh | PA |
| TASTY BAKING COMPANY – HUNTING PARK AVENUE | PHILADELPHIA | PA |
| TASTY BAKING COMPANY INCORPORATED | PHILADELPHIA | PA |
| TATE JONES AND COMPANY, INCORPORATED | PITTSBURGH | PA |
| Tate Jones Company | Beaver Falls | PA |
| TAWS AND HARTMAN | PHILADELPHIA | PA |
| Taylor Forge & Pipe Works | Carnegie | PA |
| TAYLOR-WHARTON IRON AND STEEL COMPANY | EASTON | PA |
| TECH FOOD PRODUCTS COMPANY | PITTSBURGH | PA |
| Teledyne | Monaca | PA |
| Teledyne Vasco | Monaca | PA |
| TELEDYNE, INCORPORATED | WAYNESBORO | PA |
| TELEDYNE-COLUMBIA-SUMMERHILL | SCOTTSDALE | PA |
| TEMPLE BOILER | PHILADELPHIA | PA |
| TEMPLE COVENANT OF PEACE | EASTON | PA |
| TEMPLE FURNACE | TEMPLE | PA |
| TEMPLE HOSPITAL | PHILADELPHIA | PA |
| TEMPLE IRON COMPANY | READING | PA |
| TEMPLE IRON COMPANY | FORTY FORT | PA |
| TEMPLE IRON COMPANY | TEMPLE | PA |
| TEMPLE IRON COMPANY | WYOMING | PA |
| TEMPLE IRON COMPANY | SCRANTON | PA |
| TEMPLE IRON COMPANY | BENNETT | PA |
| TEMPLE IRON COMPANY | PECKVILLE | PA |
| Temple School of Technology | PA | |
| Temple University | Philadelphia | PA |
| TEMPLE UNIVERSITY – HOSPITAL | PHILADELPHIA | PA |
| TEMPLE UNIVERSITY – LIFE & BIO-SCIENCES BUILDING | PHILADELPHIA | PA |
| TEMPLE UNIVERSITY – MEDICAL SCHOOL | PHILADELPHIA | PA |
| TEMPLE UNIVERSITY – SOCIAL SCIENCE BUILDING | PHILADELPHIA | PA |
| Temple University Hospital | Philadelphia | PA |
| Temple University, Social Science Building | Philadelphia | PA |
| TERE WOODRING AND COMPANY | HAZLETON | PA |
| TERROR (USS) | PHILADELPHIA | PA |
| TETSNER DYEING CO | PHILADELPHIA | PA |
| TETZNER DYEING COMPANY | PHILADELPHIA | PA |
| Texas Company | Marcus Hook | PA |
| TEXAS EASTERN – PENN JERSEY TRANSMISSION CORP. | LILLY | PA |
| TEXAS EASTERN – PENN JERSEY TRANSMISSION CORP. | PERULACK | PA |
| TEXAS EASTERN – PENN JERSEY TRANSMISSION CORP. | BOYERTOWN | PA |
| TEXAS EASTERN – PENN JERSEY TRANSMISSION CORP. | GRANTVILLE | PA |
| TEXAS EASTERN – PENN JERSEY TRANSMISSION CORP. | BECHTELSVILLE | PA |
| TEXTILE MACHINE WORKS | READING | PA |
| THADDEUS STEVENS INDUSTRIAL SCHOOL | LANCASTER | PA |
| THALHEIMER BROTHERS INC | PHILADELPHIA | PA |
| THE AMERICAN PULLEY COMPANY | PHILADELPHIA | PA |
| The Board Of Public Education Service Center | Pittsburgh | PA |
| THE BUDD CO | PHILADELPHIA | PA |
| THE FEDERAL BUILDING | PITTSBURGH | PA |
| The Hill School | Pottstown | PA |
| THE MERCERSBURG ACADEMY | MERCERSBURG | PA |
| The O. Hommel Company | Carnegie | PA |
| The Patterson-Kelley Co Inc | East Stroudsburg | PA |
| THE PENNSYLVANIA WATER COMPANY | NADINE | PA |
| The Philip Carey Mfg Corp | Philadelphia | PA |
| The Pierce Glass Company | Port Allegany | PA |
| The U G I Corp | Harrisburg | PA |
| The U G I Corp | Reading | PA |
| THE YORKTOWNE HOTEL | YORK | PA |
| THEODORE E. MOSER | PHILADELPHIA | PA |
| THEODORE PRESSER | YEADON | PA |
| Thermal Engineering Inc | Allentown | PA |
| Thermal Engineering Inc | Lehigh Valley | PA |
| THERMAL ENGINEERING, INCORPORATED | ALLENTOWN | PA |
| THERMAL RESEARCH & ENGINEERING | CONSHOHOCKEN | PA |
| THERMAL TRANSFER CORP | MONROEVILLE | PA |
| THERMAX CO | KENNETT SQUARE | PA |
| THOMAS DOLAN AND COMPANY | PHILADELPHIA | PA |
| THOMAS F. DEEGAN | PHILADELPHIA | PA |
| THOMAS H. GRIGG | PHILADELPHIA | PA |
| THOMAS IRON COMPANY | HELLERSTOWN | PA |
| THOMAS IRON COMPANY | HOKENDAUQUA | PA |
| THOMAS IRON COMPANY | ALBURTIS | PA |
| THOMAS JAGGERS | PHILADELPHIA | PA |
| THOMAS JEFFERSON HOSPITAL | PHILADELPHIA | PA |
| THOMAS KENT MANUFACTURING COMPANY | CLIFTON HEIGHTS | PA |
| THOMAS MAY PIERCE SCHOOL | PHILADELPHIA | PA |
| THOMAS ST. AND MCKEES AVE. | MCKEES ROCK | PA |
| Thomas Textile | Philadelphia | PA |
| THOMPSON BROTHERS | PHILADELPHIA | PA |
| THOS E. LUTNER | PHILADELPHIA | PA |
| Thos. Wolstenholme Sons & Co. | Philadelphia | PA |
| Three Mile Island | Dauphin County | PA |
| Three Mile Island | Middletown | PA |
| THREE MILE ISLAND NUCLEAR PLANT | MIDDLETOWN | PA |
| Three Mile Island Nuclear Station | Middletown | PA |
| Three Mile Island Power Plant | Middletown | PA |
| THRIFT DRUG STORE | JOHNSTOWN | PA |
| Tide Water Pipe Line Company | McAuley | PA |
| Tidewater Pipe Line Company | Bradford | PA |
| Tidewater Pipe Line Company | Hudsondale | PA |
| TIDEWATER STEEL COMPANY | CHESTER | PA |
| TILDEN JUNIOR HIGH – 66TH & ELMWOOD | PHILADELPHIA | PA |
| Till Distributing | Erie | PA |
| TIN MILL | ALIQUIPPA | PA |
| TIOGA COAL COMPANY | WILKES BARRE | PA |
| TIONESTA VALLEY CHEMICAL COMPANY | MAYBURG | PA |
| TIPPINS MACHINERY CO INC | PITTSBURGH | PA |
| TITAN METAL MANUFACTURING CO. | BELLEFONTE | PA |
| Titus Generating Station | Reading | PA |
| Titus Powerhouse | Reading | PA |
| TITUS STATION – UNIT HEATER | READING | PA |
| TITUSVILLE IRON WORKS | TITUSVILLE | PA |
| TOBEYHANNA SIGNAL DEPOT – BUILDING 1A-SECTION 4 | TOBEYHANNA | PA |
| TOBYHANNA SIGNAL DEPOT | TOBYHANNA | PA |
| TOBYHANNA SIGNAL DEPOT, HANGAR BUILDING | TOBYHANNA | PA |
| TOFFS INC | DORYEA | PA |
| Toolmatic Co. | Zelienople | PA |
| TOPPS BUBBLE GUM | AVOCA | PA |
| TORRANCE STATE HOSPITAL | TORRANCE | PA |
| TORRANCE STATE HOSPITAL – LONGVIEW DRIVE | TORRANCE | PA |
| TOSCO REFINING COMPANY | TRAINER | PA |
| TOWAMENCIN SCHOOL – FORTY FOOT ROAD | KULPSVILLE | PA |
| TOWER HILL CONNELLSVILLE COKE COMPANY | REPUBLIC | PA |
| TOWER HILL CONNELLSVILLE COKE COMPANY | UNIONTOWN | PA |
| Town of Harmarville – Sewage Treatment Plant | Harmarville | PA |
| TOWNSEND COMPANY | NEW BRIGHTON | PA |
| TOWNSHIP LIGHT AND POWER COMPANY | SHAMOKIN | PA |
| Township of Annville | Annville | PA |
| TR STAT NO TR #103 | ALIQUIPPA | PA |
| TRADE & CONVENTION CENTER, 34TH AND CURIE | PHILADELPHIA | PA |
| TRADERS COAL COMPANY | LAFLIN | PA |
| Trailmobile Manufacturing Company | Philadelphia | PA |
| Transcontinental Gas Pipe Line Corp | Renova | PA |
| TRANSCONTINENTAL PIPE – LINE CORP | FRAZER | PA |
| TRANSCONTINENTAL PIPE LINE CORP | FRAZER | PA |
| Trans-Lux Theatre Colonial | Harrisburg | PA |
| TREADKILL BUCK RUN COAL COMPANY | MINERSVILLE | PA |
| TREMONT LAUNDRY COMPANY | PHILADELPHIA | PA |
| Trent Incorporated | Philadelphia | PA |
| TRENT, INC. | MANAYUNK | PA |
| TREVERTON ELECTRIC LIGHT AND POWER COMPANY – POWER PLANT | TREVERTON | PA |
| TREXLER FARMS | ALLENTOWN | PA |
| TREXLER FARMS | EGYPT | PA |
| TREXLERTOWN PAPER BOX COMPANY | TREXLERTOWN | PA |
| Tri Cash & Carry Lumber Co | Beaver Falls | PA |
| Tri River Bldg. Products Inc | Greensburg | PA |
| Tri River Bldg. Products Inc | Pittsburgh | PA |
| TRI STATE METALS COMPANY | QUAKERTOWN | PA |
| TRI STATE NON FERROUS CO | QUAKERTOWN | PA |
| TRIANGLE INSULATION CO. | PHILADELPHIA | PA |
| Triangle Insulation Co., Inc. | Philadelphia | PA |
| TRIANGLE MECHANICAL CO | NORTH WALES | PA |
| TRI-CITIES WATER COMPANY – WATER FILTRATION PLANT | CHARLEROI | PA |
| TRINITY MIDDLE SCHOOL – WASHINGTON COUNTY | WASHINGTON | PA |
| TRINITY MIDDLE SCHOOL, WASHINGTON COUNTY | WASHINGTON | PA |
| TRI-STATE METALS COMPANY | QUAKERTOWN | PA |
| TROJAN POWDER CO. | SEIPLE | PA |
| TROJAN POWDER COMPANY | SEIPLE | PA |
| TROOP WATER HEATER | PITTSBURGH | PA |
| Trooper High School | Trooper | PA |
| Trost Sheet Metal Co | Erie | PA |
| TROY JACK | HUNTINGDON | PA |
| TRU KNIT INDUSTRIES | PHILADELPHIA | PA |
| TRUESDALE COLLIERY | NANTICOKE | PA |
| TRUESDALE COLLIERY | PLYMOUTH | PA |
| TRW Incorporated | Harrisburg | PA |
| Tub Prod | Koppel | PA |
| TUBALAS PRODUCTS DIVISION | BEAVER FALLS | PA |
| TUBE CITY BREWING COMPANY | MCKEESPORT | PA |
| Tuberculosis Hospital | Pittsburgh | PA |
| TURNER AND SERREL | PHILADELPHIA | PA |
| Tuscarora Oil Co., Ltd. | Harrisburg | PA |
| TWO PENN CENTER | PHILADELPHIA | PA |
| Tygart Glass | Washington | PA |
| TYLER CHARCOAL IRON TIN MILLS | WASHINGTON | PA |
| TYLER SCHOOL OF FINE ART | PHILADELPHIA | PA |
| TYLER TUBE AND PIPE COMPANY | WASHINGTON | PA |
| TYNAN INCINERATOR-DELA CITY IN | CHESTER TOWNSHIP | PA |
| TYROL DISTRIBUTORS | ALLENTOWN | PA |
| TYRONE IRON COMPANY | HARRISBURG | PA |
| TYRONE IRON COMPANY | TRYONE | PA |
| Tyson Metal Products | Pittsburgh | PA |
| U G I Corp | Harrisburg | PA |
| U G I Corp | Lancaster | PA |
| U G I Corp | Reading | PA |
| U G I CORP | HUNLOCK CREEK | PA |
| U S ALUMINUM CORP | MARIETTA | PA |
| U S BUREAU OF MINES | SCHUYKILL HAVEN | PA |
| U S BUREAU OF MINES | PITTSBURGH | PA |
| U S DEPT OF AGRICULTURE | PHILADELPHIA | PA |
| U S DEPT OF AGRICULTURE | WYNDMOOR | PA |
| U S GYPSUM CO | OAKMONT | PA |
| U S GYPSUM CO | DARMONT | PA |
| U S Steel | Braddock | PA |
| U S Steel Co | Clairton | PA |
| U S Steel Co | Irvin | PA |
| U S STEEL CORP | FAIRLESS HILLS | PA |
| U S STEEL CORP | MONROEVILLE | PA |
| U S STEEL CORP | MCKEES ROCKS | PA |
| U S Steel Office Bldg | Pittsburgh | PA |
| U S STEEL TUBE | MC KEESPORT | PA |
| U. S. ARMY RESERVE CENTER | PITTSBURGH | PA |
| U. S. BUREAU OF MINES | BRUCETON | PA |
| U. S. BUREAU OF MINES | PITTSBURGH | PA |
| U. S. BUREAU OF MINES | BRICETON | PA |
| U. S. BUREAU OF MINES | SWEDELAND | PA |
| U. S. BUREAU OF MINES – ALLEGHENY CITY | BRACETON | PA |
| U. S. BUREAU OF MINES – SNOWDEN TWP. | BRUCETON | PA |
| U. S. HOFFMAN MACHINERY | SCRANTON | PA |
| U. S. STEEL | CLAIRTON | PA |
| U. S. STEEL CHEMICAL PLANT – NEVILLE ISLAND | PITTSBURGH | PA |
| U. S. STEEL CORPORATION | AMBRIDGE | PA |
| U. S. STEEL CORPORATION | BERWYN | PA |
| U. S. STEEL CORPORATION | CLAIRTON | PA |
| U. S. STEEL CORPORATION | FAIRLESS | PA |
| U. S. STEEL CORPORATION | MCKEES ROCKS | PA |
| U. S. STEEL CORPORATION – AMBRIDGE PLANT | AMBRIDGE | PA |
| U. S. STEEL CORPORATION – ANTHRACENE PILOT PLANT – APPLIED RESEARCH LAB | CLAIRTON | PA |
| U. S. STEEL CORPORATION – ANTHRACENE PILOT PLANT – APPLIED RESEARCH LABORATORY | CLAIRTON | PA |
| U. S. STEEL CORPORATION – APPLIED RESEARCH CENTER | MONROEVILLE | PA |
| U. S. STEEL CORPORATION – APPLIED RESEARCH LAB | MONROEVILLE | PA |
| U. S. STEEL CORPORATION – APPLIED RESEARCH LAB – STATION NUMBER 2 | UNIVERSAL | PA |
| U. S. STEEL CORPORATION – APPLIED RESEARCH LAB. | MONROEVILLE | PA |
| U. S. STEEL CORPORATION – APPLIED RESEARCH LAB. – ANTHRACENE PILOT PLANT | CLAIRTON | PA |
| U. S. STEEL CORPORATION – ARTHUR G. MCKEE & CO. – FAIRLESS WORKS | FAIRLESS | PA |
| U. S. STEEL CORPORATION – BATTERIES #10, 11 & 12 | CLAIRTON | PA |
| U. S. STEEL CORPORATION – BENSOL BOILER HOUSE – CLAIRTON WORKS | CLAIRTON | PA |
| U. S. STEEL CORPORATION – BENZINE PLANT | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CARRIE FURNACE | RANKIN | PA |
| U. S. STEEL CORPORATION – CARRIE FURNACES | RANKIN | PA |
| U. S. STEEL CORPORATION – CLAIRTON BY PRODUCT COKE WORKS | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON COKE & COAL CHEMICAL WORKS | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON COKE & COAL CHEMICAL WORKS – RUBEL | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON WORKS | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON WORKS – B H NBR 2 | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON WORKS – BENGAIL PLANT GATE | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON WORKS – HOT PITCH TANK | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON WORKS – POWER HOUSE 2 | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLAIRTON WORKS TAR DISTILLATION PLANT | CLAIRTON | PA |
| U. S. STEEL CORPORATION – CLARTON JOB | MCKEES ROCKS | PA |
| U. S. STEEL CORPORATION – COKE OVEN DIVISION | CLAIRTON | PA |
| U. S. STEEL CORPORATION – DUQUESNE WORKS | DUQUESNE | PA |
| U. S. STEEL CORPORATION – DUQUESNE WORKS – OXYGEN PLANT, RIVER PUMP HOUSE | DUQUESNE | PA |
| U. S. STEEL CORPORATION – DUQUESNE WORKS – STATION NO 13 | DUQUESNE | PA |
| U. S. STEEL CORPORATION – DUQUESNE WORKS – STEEL WORKS | DUQUESNE | PA |
| U. S. STEEL CORPORATION – EDGAR THOMSON WORKS | BRADDOCK | PA |
| U. S. STEEL CORPORATION – EDGAR THOMSON WORKS – BRADDOCK, PENNA. | BESSEMER | PA |
| U. S. STEEL CORPORATION – EMERGENCY HOSPITAL – HOMESTEAD DISTRICT WORKS | MUNHALL | PA |
| U. S. STEEL CORPORATION – EMRG HOSP HOMESTEAD DISTRICT WORKS | MUNHALL | PA |
| U. S. STEEL CORPORATION – FAIRLESS PA | FAIRLESS HILLS | PA |
| U. S. STEEL CORPORATION – FAIRLESS WORKS | FAIRLESS | PA |
| U. S. STEEL CORPORATION – FAIRLESS WORKS | MORRISVILLE | PA |
| U. S. STEEL CORPORATION – FAIRLESS WORKS | FAIRLESS HILLS | PA |
| U. S. STEEL CORPORATION – HOMESTEAD WORKS | HOMESTEAD | PA |
| U. S. STEEL CORPORATION – IRVIN WORKS | DRAVOSBURG | PA |
| U. S. STEEL CORPORATION – IRVIN WORKS | IRVIN | PA |
| U. S. STEEL CORPORATION – JACK SMITH – FAIRLESS WORKS | MORRISVILLE | PA |
| U. S. STEEL CORPORATION – JJ WHITE – JACK SMITH – FAIRLESS WORKS | MORRISVILLE | PA |
| U. S. STEEL CORPORATION – JOHNSTOWN WORKS | JOHNSTOWN | PA |
| U. S. STEEL CORPORATION – JOHNSTOWN WORKS – POWER HOUSE | JOHNSTOWN | PA |
| U. S. STEEL CORPORATION – METALLURGICAL LAB | VANDERGRIFT | PA |
| U. S. STEEL CORPORATION – NATIONAL TUBE DIVISION – NATIONAL WORKS | MCKEESPORT | PA |
| U. S. STEEL CORPORATION – NATIONAL WORKS | MCKEESPORT | PA |
| U. S. STEEL CORPORATION – PATT. #10, 11, & 12 | CLAIRTON | PA |
| U. S. STEEL CORPORATION – R. G. PEILIKER – APPLIED RESEARCH LAB. | MONROEVILLE | PA |
| U. S. STEEL CORPORATION – RANKIN WORKS #2 TURBO BLOWER | RANKIN | PA |
| U. S. STEEL CORPORATION – RANKIN WORKS #2 TURBO BLOWER – RANKIN MILL | RANKIN | PA |
| U. S. STEEL CORPORATION – RESEARCH CENTER | MONROEVILLE | PA |
| U. S. STEEL CORPORATION – SAXONBURG SINTERING PLANT | HOUSEVILLE | PA |
| U. S. STEEL CORPORATION – STEEL WORKS – DUQUESNE WORKS | DUQUESNE | PA |
| U. S. STEEL CORPORATION – TAR DISTILLATION PLANT | CLAIRTON | PA |
| U. S. STEEL CORPORATION – VANDERGRIFT WORKS | VANDERGRIFT | PA |
| U. S. STEEL CORPORATION – WORKS AUDITOR – CLAIRTON WORKS | CLAIRTON | PA |
| U. S. STEEL CORPORATION – WYETH LABS | WEST CHESTER | PA |
| U. S. STEEL JOB | PHILADELPHIA | PA |
| U. S. STEEL RESEARCH – RESEARCH LAB | MONROEVILLE | PA |
| U. S. STEEL URBAN WORKS | MCKEES ROCKS | PA |
| U.G.I. COMPANY | PHILADELPHIA | PA |
| U.S. AIR FORCE – Olmsted Field | MIDDLETOWN | PA |
| U.S. BUREAU OF MINES | BRUCETON | PA |
| U.S. BUREAU OF MINES EXPERIMENTAL MINE | BRUCETON | PA |
| U.S. Customs Building – Court Rooms | Philadelphia | PA |
| U.S. Engineers Susquehanna River Flood Control | Eiles Barre | PA |
| U.S. GOVERNMENT – Special Ordinance Plant | YORK | PA |
| U.S. GOVERNMENT SUPPY DEPOT – QUATERMASTERS | PHILADELPHIA | PA |
| U.S. Hoffman Machinery Corp. | Pittsburgh | PA |
| U.S. Mint | Philadelphia | PA |
| U.S. NACAL AIR DIVISION | JOHNSVILLE | PA |
| U.S. NAVAL AIR STATION WILLOW GROVE | WILLOW GROVE | PA |
| U.S. NAVAL SHIPYARD | Philadelphia | PA |
| U.S. Navy – Naval Ammunition Depot Central Heating Plant – Fort Miffin | PHILADELPHIA | PA |
| U.S. NAVY YARD – PHILADELPHIA NAVAL YARD | PHILADELPHIA | PA |
| U.S. Signal Corps – Administration Building | Tobyhanna | PA |
| U.S. Steel | Fairless Hills | PA |
| U.S. Steel | Monroeville | PA |
| U.S. STEEL | PITTSBURGH | PA |
| U.S. STEEL | GREEN CTY | PA |
| U.S. STEEL | DRAVOSBURG | PA |
| U.S. STEEL | HOMESTEAD | PA |
| U.S. STEEL | DUQUESNE | PA |
| U.S. STEEL | RANKIN | PA |
| U.S. STEEL – CLAIRTON WORKS | CLAIRTON | PA |
| U.S. STEEL – DUQUESNE WORKS | DUQUESNE | PA |
| U.S. STEEL – DUQUESNE WORKS – CENTRAL BOILER HOUSE | DUQUESNE | PA |
| U.S. STEEL – HOMESTEAD STEEL WORKS | HOMESTEAD | PA |
| U.S. STEEL – IRVIN PLANT | WEST MIFFLIN | PA |
| U.S. STEEL – NATIONAL TUBE WORKS – TUBES MANUFACTURING PLANT | MCKEESPORT | PA |
| U.S. Steel – No. 13 Benzine Still | Clairton | PA |
| U.S. STEEL (CLAIRTON WORKS) | CLAIRTON | PA |
| U.S. STEEL (FAIRLESS WORKS) | FAIRLESS HILLS | PA |
| U.S. STEEL BUILDING – GRANT STREET | PITTSBURGH | PA |
| U.S. STEEL CLAIRTON WORKS | CLAIRTON | PA |
| U.S. STEEL CORP | MCKEES ROCKS | PA |
| U.S. STEEL CORP – CLAIRTON WORKS | CLAIRTON | PA |
| U.S. STEEL CORP (a/k/a National Tube) | ELLWOOD CITY | PA |
| U.S. STEEL CORP. | BRADDOCK | PA |
| U.S. STEEL CORP. | CLAIRTON | PA |
| U.S. STEEL CORP. | FAIRLESS | PA |
| U.S. STEEL CORP. | HOMESTEAD | PA |
| U.S. STEEL CORP. | MONROEVILLE | PA |
| U.S. STEEL CORP; DUQUESNE WORKS | DUQUESNE | PA |
| U.S. STEEL CORP; HOMESTEAD WORKS | HOMESTEAD | PA |
| U.S. Steel Corporation | Morrisville | PA |
| U.S. Steel Corporation | Pittsburgh | PA |
| U.S. Steel Corporation | Vandegrift | PA |
| U.S. STEEL CORPORATION | CLAIRTON | PA |
| U.S. STEEL CORPORATION – CLAIRTON PLANT | CLAIRTON | PA |
| U.S. Steel Mill, Fairless Hills | Morrisville | PA |
| U.S. STEEL PLANT | NEVILLE ISLAND | PA |
| U.S. STEEL, CARRIE FURNACE, SINTER PLANT | RANKIN | PA |
| U.S. STEEL, CLAIRTON | CLAIRTON | PA |
| U.S. STEEL, CLAIRTON WORKS | CLAIRTON | PA |
| U.S. STEEL, CLAIRTON WORKS, BENZENE BOILER HOUSE | CLAIRTON | PA |
| U.S. STEEL, CLAIRTON WORKS, POWER HOUSE #2 | CLAIRTON | PA |
| U.S. STEEL, DUQUESNE | DUQUESNE | PA |
| U.S. STEEL, HEADQUARTER BUILDING, RESEARCH CENTER | MONROEVILLE | PA |
| U.S. STEEL, HOMESTEAD WORKS | HOMESTEAD | PA |
| U.S. STEEL, NATIONAL TUBE WORKS | MCKEESPORT | PA |
| U.S. STEEL, NEVILLE ISLAND | PITTSBURGH | PA |
| U.S. STEEL, RANKIN | RANKIN | PA |
| U.S. STEEL, SINTER PLANT #1 | SAXONBURG | PA |
| U.S. Steel/USX (Christy Park) | McKeesport | PA |
| U.S.S. ALDERBARAN | CHESTER | PA |
| U.S.S. CHEMICALS | Neville Island | PA |
| U.S.S. DIVISION OF USX CORPORATION | CLAIRTON | PA |
| U.S.S. DIVISION OF USX CORPORATION | HOMESTEAD | PA |
| U.S.S. GWIN | PHILADELPHIA | PA |
| U.S.S. HANK [SHIP] | CHESTER | PA |
| U.S.S. HANK DD-702 | CHESTER | PA |
| U.S.S. MONROVIA [SHIP] | PHILADELPHIA | PA |
| U.S.S. VERMILION | CHESTER | PA |
| UGI BUILDING | PHILADELPHIA | PA |
| UKRANIAN CATHEDRAL | CHESTER | PA |
| UNDERGROUND | MCKEES ROCKS | PA |
| Underwood Coal Co | Scranton | PA |
| UNION BOILER | PHILADELPHIA | PA |
| Union Carbide & Carbon Chemical Corp. | Duquesne | PA |
| Union Carbide Corp. | Harrisburg | PA |
| UNION COAL COMPANY | MT. CARMEL | PA |
| UNION COAL COMPANY | SHAMOKIN | PA |
| UNION COAL COMPANY, SCOTT COLLIERY | MT. CARMEL | PA |
| UNION COAL COMPANY, SCOTT SHAFT | MT. CARMEL | PA |
| UNION DISH COMPANY | BRADFORD | PA |
| UNION DRAWN STEEL COMPANY | BEAVER FALLS | PA |
| UNION ELECTRIC COMPANY – MANUFACTURING PLANT | PITTSBURGH | PA |
| UNION ELECTRIC STEEL | CARNEGIE | PA |
| UNION ELECTRIC STEEL COMPANY – STEEL PLANT | CARNEGIE | PA |
| UNION ELECTRIC STEEL CORP | CARNEGIE | PA |
| UNION ELETRIC | BURGETTSTOWN | PA |
| UNION ELETRIC | CARNEGIE | PA |
| UNION ICE COMPANY | PITTSBURGH | PA |
| UNION IRON WORKS | ERIE | PA |
| UNION LEAGUE CLUB | PHILADELPHIA | PA |
| UNION METAL MANUFACTURING | EAST STROUDSBURG | PA |
| UNION METAL MANUFACTURING | STROUDSBURG | PA |
| UNION METAL MANUFACTURING EAST | STROUDSBURG | PA |
| UNION MILLS PAPER MANUFACTURING COMPANY | NEW HOPE | PA |
| UNION PAVING COMPANY | BRIDGEPORT | PA |
| UNION PAVING COMPANY | PHILADELPHIA | PA |
| UNION PAVING COMPANY | SPRINGHOUSE | PA |
| Union Railroad | Braddock | PA |
| UNION SPECIALTIES | VERONA | PA |
| UNION SPRING & MFG CO | NEW KENSINGTON | PA |
| Union Spring & Mfg. Co. | New Kensington | PA |
| UNION SPRING AND MFG CO | NEW KENSLINGTON | PA |
| UNION SPRING MANUFACTURING COMPANY | PITTSBURGH | PA |
| UNION SPRING MANUFACTURING COMPANY | NEW KENSINGTON | PA |
| UNION STATION | PITTSBURGH | PA |
| Union Steel | Pittsburgh | PA |
| Union Steel Casting | Pittsburgh | PA |
| UNION STEEL COMPANY | PITTSBURGH | PA |
| UNION STEEL COMPANY | DONORA | PA |
| UNION SWITCH AND SIGNAL COMPANY | SWISSVALE | PA |
| UNION TRACTION COMPANY | PHILADELPHIA | PA |
| Union Trust Building | Pittsburgh | PA |
| Uniontown Demolition | Point Marion | PA |
| Uniontown Hospital | Uniontown | PA |
| UNIONTOWN NEWSPAPER BUILDING | UNIONTOWN | PA |
| UNIONTOWN SENIOR HIGH SCHOOL | UNIONTOWN | PA |
| Uniroyal Rubber Company | Philadelphia | PA |
| UNIT RAIL ANCHOR CORP | PITTSBURG | PA |
| United – Atkinson, Incorporated | Erie | PA |
| United Atkinson Inc | Erie | PA |
| UNITED CHURCH OF CHRIST | BETHLEHEM | PA |
| UNITED CONTAINER CORPORATION | PHILADELPHIA | PA |
| UNITED ELECTRIC COMPANY – ELECTRIC PLANT | LEMOYNE | PA |
| UNITED ENGINE AND FDY COMPANY | PITTSBURGH | PA |
| United Engineering | Pittsburgh | PA |
| UNITED ENGINEERING & FOUNDRY | VANDERGRIFT | PA |
| United Engineering & Foundry Company | Homestead | PA |
| United Engineering & Foundry Company | Pittsburgh | PA |
| United Engineering & Foundry Company | Titusville | PA |
| UNITED ENGINEERING & FOUNDRY COMPANY | NEW CASTLE | PA |
| UNITED ENGINEERING AND FOUNDRY COMPANY | PITTSBURGH | PA |
| UNITED ENGINEERING AND FOUNDRY COMPANY | VANDERGRIFT | PA |
| UNITED ENGR & FOUNDRY CO | VANDERGRIFT | PA |
| UNITED ENGR & FOUNDRY CO | PITTSBURGH | PA |
| UNITED ENGR AND FDRY CO | VANDERGRIFT | PA |
| United Gas Improvement Co Philadelphia Gas Works | Philadelphia | PA |
| UNITED GAS IMPROVEMENT COMPANY – GAS PLANT | STEELTON | PA |
| UNITED GAS IMPROVEMENT COMPANY – HOLDER STATION | GERMANTOWN | PA |
| UNITED GAS IMPROVEMENT COMPANY – POWER PLANT | WAYNE | PA |
| United Gilsonite Lab. | Scranton | PA |
| United Industrial Supply Co | Erie | PA |
| UNITED REFINING CO | WARREN | PA |
| United Refining Co. | Warren | PA |
| UNITED REFINING COMPANY | WARREN | PA |
| UNITED ROOFING AND MANUFACTURING COMPANY | MARCUS HOOK | PA |
| UNITED STATES ALUMINUM OF AMERICA | PITTSBURGH | PA |
| UNITED STATES ASBESTOS | MANHEIM | PA |
| UNITED STATES ASBESTOS COMPANY | MANHEIM | PA |
| UNITED STATES ASBESTOS, DIVISION OF RAYBESTOS MANHATTAN INCORPORATED | MANHEIM | PA |
| UNITED STATES ASBESTOS, DIVISION OF RAYBESTOS MANHATTAN, INCORPORATED | MANHEIM | PA |
| UNITED STATES COAL AND COKE COMPANY | PITTSBURGH | PA |
| UNITED STATES DEPARTMENT OF COMMERCE, BUREAU OF MINES, EXPERIMENTAL STATION | PITTSBURGH | PA |
| UNITED STATES GOVERNMENT SHELL LOADING PLANT #1 | TULLYTOWN | PA |
| UNITED STATES GYPSUM | PHILADELPHIA | PA |
| UNITED STATES IRON AND TIN PLATE MANUFACTURING COMPANY | DEMMLER | PA |
| UNITED STATES MINT | PHILADELPHIA | PA |
| UNITED STATES NAVAL HOME | PHILADELPHIA | PA |
| UNITED STATES NAVAL HOSPITAL | PHILADELPHIA | PA |
| UNITED STATES NAVY YARD | LEAGUE ISLAND | PA |
| UNITED STATES NAVY YARD DRY DOCKS | LEAGUE ISLAND | PA |
| UNITED STATES PIPE AND FOUNDRY COMPANY | SCOTTDALE | PA |
| UNITED STATES POWDER COMPANY, EXPLOSIVE DIVISION | MT. BRADDOCK | PA |
| UNITED STATES SANITARY MANUFACTURING COMPANY | MONACA | PA |
| UNITED STATES SEAMLESS TUBE COMPANY | CHRISTY PARK | PA |
| UNITED STATES STEEL | DUQUESNE | PA |
| UNITED STATES STEEL | ELLWOOD CITY | PA |
| UNITED STATES STEEL | FAIRLESS HILLS | PA |
| UNITED STATES STEEL | MCKEESPORT | PA |
| UNITED STATES STEEL | AMERICAN BRIDGE | PA |
| UNITED STATES STEEL | DONORA | PA |
| UNITED STATES STEEL COMPANY | HOMESTEAD | PA |
| UNITED STATES STEEL CORP | AMBRIDGE | PA |
| United States Steel Corp. – Applied Research Laboratory | Universal | PA |
| United States Steel Corporation | Braddock | PA |
| United States Steel Corporation | Clairton | PA |
| United States Steel Corporation | Duquesne | PA |
| United States Steel Corporation | Fairless | PA |
| United States Steel Corporation | Homestead | PA |
| United States Steel Corporation | Monroeville | PA |
| United States Steel Corporation | Pittsburgh | PA |
| United States Steel Corporation | McKees Rocks | PA |
| UNITED STATES STEEL CORPORATION | NEVILLE ISLAND | PA |
| UNITED STATES STEEL CORPORATION | DRAVOSBURG | PA |
| United States Steel Corporation – Irvin Works | West Mifflin | PA |
| UNITED STATES STEEL CORPORATION ORDNANCE DEPARTMENT | NEVILLE ISLAND | PA |
| UNITED STATES STEEL, EDGAR THOMPSON WORKS | PITTSBURGH | PA |
| UNITED STATES STEEL/USX | MUNHALL | PA |
| UNITED STATES VETERANS HOSPITAL | COATESVILLE | PA |
| UNITED STATES WAR VETERANS HOSPITAL | COATESVILLE | PA |
| United Steel and Wire | Wilkes Barre | PA |
| UNITED STEEL BARRELL | PHILADELPHIA | PA |
| UNITED STEEL CORP – DUQUESNE WORKS | DUQUESNE | PA |
| UNITED TRACTION COMPANY | PITTSBURGH | PA |
| UNITY HOUSE – ADMINISTRATION BUILDING | BUSHKILL | PA |
| UNIV ATLAS CEM DIV OF USS CORP | UNIVERSAL | PA |
| UNIV. ATLAS CEMENT | PITTSBURGH | PA |
| UNIV. WELDING | EXPORT | PA |
| UNIVERSAL ATLAS | NORTHHAMPTON | PA |
| UNIVERSAL ATLAS CEMENT | NORTHAMPTON | PA |
| UNIVERSAL ATLAS CEMENT | UNIVERSAL | PA |
| UNIVERSAL ATLAS CEMENT | PITTSBURGH | PA |
| Universal Atlas Cement Div. United States Steel Corporation | Universal | PA |
| Universal Cyclops | Bridgeville | PA |
| UNIVERSAL CYCLOPS CORP | PITTSBURGH | PA |
| UNIVERSAL CYCLOPS CORP | TITUSVILLE | PA |
| UNIVERSAL CYCLOPS STEEL | TITUSVILLE | PA |
| UNIVERSAL CYCLOPS STEEL COMPANY | TITUSVILLE | PA |
| Universal Cyclops Steel Corporation-Pittsburgh Works | Pittsburgh | PA |
| UNIVERSAL CYCLOPS STEEL MILL | TITUSVILLE | PA |
| UNIVERSAL DYE WORKS | PHILADELPHIA | PA |
| UNIVERSAL DYE WORKS | TACONY | PA |
| Universal Insualtion Company | Philadelphia | PA |
| Universal Insulation Co. | Philadelphia | PA |
| UNIVERSAL OIL PRODUCTS – KENDALL REFINING CO. | BRADFORD | PA |
| UNIVERSAL RUBBER PRODUCTS COMPANY | ZELIENOPLE | PA |
| UNIVERSAL RUNDLE CO | MAHONINGTOWN | PA |
| UNIVERSAL RUNDLE CO | NEW CASTLE | PA |
| UNIVERSAL RUNDLE CO – NEW CASTLE MACHINE PLANT | NEW CASTLE | PA |
| UNIVERSAL RUNDLE CO – NEW CASTLE PLANT | NEW CASTLE | PA |
| UNIVERSAL RUNDLE CO – NEW CASTLE VC PLANT | MAHONINGTOWN | PA |
| UNIVERSAL RUNDLE CO – NEW CASTLE VC PLANT | NEW CASTLE | PA |
| UNIVERSAL RUNDLE CO – VITREOUS CHINA PLANT | MAHONINGTOWN | PA |
| Universal Werehouse | Philadelphia | PA |
| UNIVERSAL-RUNDLE CORPORATION | NEW CASTLE | PA |
| UNIVERSITY CITY HIGH SCHOOL | PHILADELPHIA | PA |
| UNIVERSITY CITY HIGH SCHOOL – FILBERT STREET | PHILADELPHIA | PA |
| UNIVERSITY CLUB | PHILADELPHIA | PA |
| University of Pennsylvania | Philadelphia | PA |
| UNIVERSITY OF PENNSYLVANIA – 8TH FLOOR HOSPITAL | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – ADMINISTRATION BUILDING | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – CHEMISTRY BUILDING | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – DENTAL SCHOOL | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – DENTAL SCHOOL – 42ND & SPRUCE STREETS | PHILADELPHIA | PA |
| University of Pennsylvania – Hospital | Philadelphia | PA |
| UNIVERSITY OF PENNSYLVANIA – HYPERBARIC FACILITIES | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – LAW SCHOOL | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – LIBERAL ARTS | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – MALONEY BUILDING | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – MALONEY BUILDING – ROOM 636 | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – MEDICAL CENTER – RESIDENCE BUILDING | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – MEDICAL LABORATORY | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – MEDICAL SCHOOL | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – MUSEUM | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – OPERATING ROOM | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – PENTHOUSE | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – RAVDIN BUILDING HOSPITAL | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – SOCIAL SCIENCE CENTER | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – STEAM DISTRIBUTION SYSTEM | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – THERAPEUTIC LABORATORY | PHILADELPHIA | PA |
| University of Pennsylvania – Undergraduate Library | Philadelphia | PA |
| UNIVERSITY OF PENNSYLVANIA – VETERINARY RESEARCH | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA – VETERINARY SCHOOL | PHILADELPHIA | PA |
| University of Pennsylvania Hyperbarric Test Complex | Philadelphia | PA |
| UNIVERSITY OF PENNSYLVANIA, GYMNASIUM | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA, HYPERBARIC FACILITIES | PHILADELPHIA | PA |
| UNIVERSITY OF PENNSYLVANIA, MEDICAL CENTER, RESIDENCE BUILDING | PHILADELPHIA | PA |
| University Of Pittsburgh | Pittsburgh | PA |
| University of Pittsburgh – Cathedral of Learning | Pittsburgh | PA |
| UNIVERSITY OF PITTSBURGH – LEARNING RESEARCH AND DEVELOPMENT CENTER | PITTSBURGH | PA |
| University of Pittsburgh, Cathedral of Learning | PA | |
| University of Pittsburgh, Mellon Institute of Industrial Research | Pittsburgh | PA |
| University Square Condominiums | Pittsburgh | PA |
| Upper Darby High School | Drexel Hill | PA |
| UPPER DARBY HIGH SCHOOL – NORTH LANSDOWNE AVENUE | DREXEL HILL | PA |
| UPPER MANOVER TWP NORTH OF E GREENV | MONTGOMERY COUNTY | PA |
| Upper Milford School | Upper Milford | PA |
| URSINUS COLLEGE – DINING ROOM | COLLEGEVILLE | PA |
| US ALUMINAM COMPANY | NEW KENSINGTON | PA |
| US ALUMINUM COMPANY | NEW KENSINGTON | PA |
| US ARMY RESERVE CENTER | READING | PA |
| US ARMY SUPPLY BASE | PHILADELPHIA | PA |
| Us Bureau Of Mines | Bruceton | PA |
| US COURTHOUSE | PHILADELPHIA | PA |
| US COURTHOUSE & OFFICE BUILDING | PHILADELPHIA | PA |
| US Custom House | Philadelphia | PA |
| US GYPSUM CO | PHILADELPHIA | PA |
| US MINT | PHILADELPHIA | PA |
| US MINT – 4TH & ARCH STREET | PHILADELPHIA | PA |
| US NAVY | PHILADELPHIA | PA |
| US NAVY YARD | PHILADELPHIA | PA |
| US Post Office | Philadelphia | PA |
| US Sanitary Mfg. | Monaca | PA |
| Us Steel | Clairton | PA |
| Us Steel | Morrisville | PA |
| Us Steel | Mckees Rocks | PA |
| US Steel | Fairless Hills | PA |
| US Steel | Duquesne | PA |
| US Steel | Carrie Furnace | PA |
| US Steel | Shiremanstown | PA |
| US Steel | Braddock | PA |
| US Steel | Hillsville | PA |
| US Steel | Homestead | PA |
| US Steel | Dravosburg | PA |
| US STEEL | AMBRIDGE | PA |
| US STEEL | IRVIN | PA |
| US STEEL | FAIRBANK | PA |
| US STEEL | IRVIN WORKS | PA |
| US STEEL | PITTSBURGH | PA |
| US STEEL | ELLWOOD CITY | PA |
| US STEEL | MONROEVILLE | PA |
| US STEEL | MCKEESPORT | PA |
| US STEEL | FAIRLESS | PA |
| US STEEL | JOHNSTOWN | PA |
| US STEEL – CARRIE FURNACE – SINTER PLANT | RANKIN | PA |
| US STEEL – CLAIRTON WORKS | CLAIRTON | PA |
| US STEEL – CLAIRTON WORKS – BENZENE BOILER HOUSE | CLAIRTON | PA |
| US STEEL – CLAIRTON WORKS – POWER HOUSE #2 | CLAIRTON | PA |
| US STEEL – EDGAR THOMSON WORKS | BRADDOCK | PA |
| US STEEL – HEADQUARTER BUILDING – RESEARCH CENTER | MONROEVILLE | PA |
| US STEEL – HOMESTEAD WORKS | Homestead | PA |
| US STEEL – HOMESTEAD WORKS | PITTSBURGH | PA |
| US STEEL – NEVILLE ISLAND | PITTSBURGH | PA |
| US Steel – No. 2 Power House New G.E. | Clairton | PA |
| US STEEL – SINTER PLANT #1 | SAXONBURG | PA |
| US STEEL – WHEEL & AXLE PLANT | MCKEES ROCK | PA |
| Us Steel Co. | Pittsburgh | PA |
| US STEEL COMPANY | MORRISVILLE | PA |
| US STEEL COMPANY | DRAVOSBURG | PA |
| US STEEL CORP | DUQUESNE | PA |
| US STEEL CORP | IRVIN | PA |
| US STEEL CORP | FAIRLESS HILLS | PA |
| US STEEL CORP | JOHNSTOWN | PA |
| US STEEL CORP | BRADDOCK | PA |
| US STEEL CORP IMPERIAL | W OIL CITY | PA |
| US STEEL CORP IMPERIAL W | OIL CITY | PA |
| US STEEL CORPORATION EDGAR THOMSON WORKS | BRADDOCK | PA |
| US STEEL CORPORATION, HOMESTEAD DISTRICT WORKS | PITTSBURGH | PA |
| US STEEL FAIRLESS HILLS WORKS | MORRISVILLE | PA |
| US Steel Irvin Works | West Mifflin | PA |
| US Steel Mill | McKees Rocks | PA |
| US Steel Mill, Fairless Hills | Morrisville | PA |
| US Steel National Tube | MxKeesport | PA |
| US STEEL TUBE | MCKEESPORT | PA |
| US STEEL TUBE | MCKEE SPORT | PA |
| US Steel, Homestead Works | Pittsburgh | PA |
| US STEEL, HOMESTEAD WORKS | HOMESTEAD | PA |
| US Steel, Irvin Works | Dravosburg | PA |
| US Steel, USX | Pittsburgh | PA |
| US VETERANS ADMINISTRATION | ALTOONA | PA |
| USG Sun Shipbuilding & Dry Dock | Chester | PA |
| USG Sun Shipbuilding Company | Chester | PA |
| USS CHICAGO PHILADELPHIA NAVAL SHIPYARD | PHILADELPHIA | PA |
| USS CONT 2567 | MCKEES ROCKS | PA |
| USS CONT. 2567 | MCKEES ROCKS | PA |
| USS HEADQUARTERS | PITTSBURGH | PA |
| USS HEADQUARTERS, GRANT STREET | PITTSBURGH | PA |
| USX | MORRISVILLE | PA |
| USX | FAIRLESS HILLS | PA |
| USX CORPORATION | PITTSBURGH | PA |
| USX IRVING WORKS | WEST MIFFLIN | PA |
| USX IRVING WORKS | PITTSBURGH | PA |
| USX STEEL | DRAVOSBURG | PA |
| USX STEEL MILL | FAIRLESS HILLS | PA |
| USX STEEL MILL | BRACKENRIDGE | PA |
| USX STEEL MILL | CLAIRTON | PA |
| USX STEEL, CLAIRTON WORKS | PITTSBURGH | PA |
| V.C. GOLDEN | PITTSBURGH | PA |
| V.L. CAVANNA AND COMPANY | PHILADELPHIA | PA |
| VALETTI MARINE SUPPLY | PHILADELPHIA | PA |
| Valley Corp | Ardmore | PA |
| VALLEY CAMP COAL COMPANY | POLAND | PA |
| VALLEY ELECTRIC COMPANY – ELECTRIC PLANT | NEW BRIGHTON | PA |
| VALLEY ELECTRIC COMPANY – POWER PLANT | FALLSTON | PA |
| VALLEY FEDERAL SAVINGS AND LOANS ASSOCIATION | EASTON | PA |
| VALLEY FORGE | WILLOW GROVE | PA |
| Valley Forge Hospital | Phoenixville | PA |
| VALLEY FORGE HOSPITAL | WILLOW GROVE | PA |
| Valley Forge State Park | Valley Forge | PA |
| Valley Hospital | PA | |
| VALLEY ICE COMPANY | BEAVER FALLS | PA |
| VALLEY MAID INC | PHOENIXVILLE | PA |
| VALLEY MILL | COPLAY | PA |
| VALLEY MOULD AND IRON COMPANY | SHARPSVILLE | PA |
| VALLEY SUPPLY | PHILLIPSBURG | PA |
| VALLEY TRACTION COMPANY | BRIDGEPORT | PA |
| VALLEY TRACTION COMPANY, LEMOYNE | CUMBERLAND COUNTY | PA |
| Van Brunt Company | Philadelphia | PA |
| VAN DORN COMPANY HEAT TRE | MCKEES ROCKS | PA |
| VAN HORN ELY | NEW BRIGHTON | PA |
| VANADIUM ALLOYS STEEL COMPANY | MONACA | PA |
| VANADIUM ALLOYS STEEL COMPANY | LATROBE | PA |
| VANDERGRIFT ELECTRIC LIGHT AND POWER COMPANY – POWER PLANT | VANDERGRIFT | PA |
| VANDERGRIFT LAND AND IMPROVEMENT COMPANY | VANDERGRIFT | PA |
| VARE JUNIOR HIGH SCHOOL | PHILADELPHIA | PA |
| VASCO | LATROBE | PA |
| VASCO | MONACA | PA |
| VAUGH SANITARY BAKERY | BERWICK | PA |
| VCITICORP VENTURE CAPITAL | LATROBE | PA |
| VEGA (T-AK-286) | CHESTER | PA |
| VENEZUELA GULF REFINING C | PITTSBURGH | PA |
| VENUS PEN & PENCIL | ERWINBURG | PA |
| VERNON TEXTILE CO | PHILADELPHIA | PA |
| VERTAL DIVISION | EDDYSTONE | PA |
| VERTOL DIV BOEING CO | EDDYSTONE | PA |
| VESTA COAL COMPANY | CALIFORNIA | PA |
| VESTA COAL COMPANY | ALLENPORT | PA |
| VESTA COAL COMPANY | WEST BROWNSVILLE | PA |
| VESTA COAL COMPANY | PITTSBURGH | PA |
| VESUVIOS CRUCIBLE CO | PITTSBURG | PA |
| VESUVIUS CRUCIBLE CO | PITTSBURGH | PA |
| VETERANS ADMINISTRATION HOSPITAL | COATESVILLE | PA |
| VETERANS ADMINISTRATION HOSPITAL | PITTSBURGH | PA |
| Veterans Hospital | Philadelphia | PA |
| VETERANS HOSPITAL | PITTSBURGH | PA |
| VETERANS HOSPITAL | ALTOONA | PA |
| VETERANS STADIUM – PATTISON AVENUE | PHILADELPHIA | PA |
| VICK MANUFACTURING DIVISION | PHILADELPHIA | PA |
| VICTOR BARWARD INDUSTRIES | PHILADELPHIA | PA |
| Victor Box Co. | Quakertown | PA |
| VICTOR CHEMICAL COMPANY | MORRISVILLE | PA |
| VICTOR CHEMICAL WORKS | MORRISVILLE | PA |
| VIKO FURNITURE | ELDRED | PA |
| VILLANOVA COLLEGE | VILLANOVA | PA |
| VILLANOVA UNIVERSITY – LAW SCHOOL BLDG. | VILLANOVA | PA |
| VILLANOVA UNIVERSITY – NEW LAW SCHOOL BLDG. | VILLANOVA | PA |
| VINTON COLLIERY COMPANY | VINTONDALE | PA |
| Visco Co. | Marcus Hook | PA |
| Viscose Company | Marcus Hook | PA |
| Viscose Company | Meadville | PA |
| VITRO **RE METALS | CANONSBURG | PA |
| VITRO RARE METALS CO. | CANONSBURG | PA |
| VOCATIONAL TECHNICAL SCHOOL | DELAWARE CITY | PA |
| VORNHOLD WALL PAPER | HULMEVILLE | PA |
| VOSTERS NURSERIES | SECANE | PA |
| VULCAN DETINNING COMPANY | NEVILLE ISLAND | PA |
| VULCAN FOUNDRY AND MACHINE COMPANY | NEW CASTLE | PA |
| VULCAN MOLD | LATROBE | PA |
| VULCANITE PAVING COMPANY | PHILADELPHIA | PA |
| Vulcanized Rubber & Plastics Co. | Morrisville | PA |
| Vulcanized Rubber Company | Morrisville | PA |
| W M H RORER COMPANY | FORT WASHINGTON | PA |
| W R Grace & Company | New Castle | PA |
| W ROSE INC | SHARON HILL | PA |
| W S ROCKWELL CO | CHALFONT | PA |
| W W Armstrong Inc | Carnegie | PA |
| W. A. MEIER GLASS CO. | ROCHESTER | PA |
| W. DEWEES WOOD COMPANY | PITTSBURGH | PA |
| W. DEWEES WOOD COMPANY | MCKEESPORT | PA |
| W. G. BALPH COMPANY | PITTSBURGH | PA |
| W. GLYDE WILKINS, C.E. | PITTSBURGH | PA |
| W. J. Hunt | Carlisle | PA |
| W. P. Duckworth | Lansdowne | PA |
| W. R. Grace | New Castle | PA |
| W.C. HAMILTON AND SON | PHILADELPHIA | PA |
| W.C. HAMILTON AND SON | LAFAYETTE | PA |
| W.C. HAMILTON AND SONS | PHILADELPHIA | PA |
| W.D. REINIGER & SONS | HATBORO | PA |
| W.F. MOSSER AND SON | ALLENTOWN | PA |
| W.G PAYNE AND COMPANY | KINGSTON | PA |
| W.G. PENNYPACKER | PHILADELPHIA | PA |
| W.G. WILKINS COMPANY | PITTSBURGH | PA |
| W.H. GRUNDY | BRISTOL | PA |
| W.H. GRUNDY AND COMPANY | BRISTOL | PA |
| W.H. HAWS FIRE BRICK COMPANY | MT. UNION | PA |
| W.H. LUDEN | READING | PA |
| W.H. PIPER AND COMPANY | LILLY | PA |
| W.H. PIPER AND COMPANY | PHILADELPHIA | PA |
| W.J. HOLLIS | READING | PA |
| W.J. MCCAHAN SUGAR REFINING | PHILADELPHIA | PA |
| W.J. MCCAHAN SUGAR REFINING AND MOLASSES COMPANY | PHILADELPHIA | PA |
| W.J. MCCAHAN SUGAR REFINING COMPANY | PHILADELPHIA | PA |
| W.J. RAINEY COMPANY | CONNELLSVILLE | PA |
| W.K. NIVER COAL COMPANY | BERLIN | PA |
| W.M. ANDERSON | PHILADELPHIA | PA |
| W.P.O. RAILROAD | PHILADELPHIA | PA |
| W.R. GRACE – VERMICULITE EXFOLIATION FACILITY – EAST CHERRY STREET | NEW CASTLE | PA |
| W.R. GRACE – VERMICULITE EXFOLIATION FACILITY – FACTORY STREET | ELLWOOD CITY | PA |
| W.R. MCTURK COAL COMPANY | GIRARDVILLE | PA |
| W.T. MCGURK COAL COMPANY | GIRARDVILLE | PA |
| W.W. DARLEY | PITTSBURGH | PA |
| W.W. EVANS MEMORIAL SCHOOL | BLOOMSBURG | PA |
| W.W. HARRISON | GLENSIDE STATION | PA |
| Wabash Pitts Railroad Powerhouse | Pittsburgh | PA |
| WABASH PITTSBURGH TERMINAL | PITTSBURGH | PA |
| WAGER AND COX | BRIDGEPORT | PA |
| WAGONERS E C SONS | BEAVER FALLS | PA |
| WAGONERS F C SONS | BEAVER FALLS | PA |
| WALKER AND KEPLER | PHILADELPHIA | PA |
| WALL & SHAND, DUKE AND VINE STS. | LANCASTER | PA |
| WALLACE-MURRAY | SCRANTON | PA |
| WALLENPAUPACK HE DEVELOPMENT | HAWLEY | PENNSYLVANIA |
| WALSTER CORP | LACKAWANNA COUNTY | PA |
| Wanamaker Garage | Philadelphia | PA |
| WANAMAKER JUNIOR HIGH SCHOOL | PHILADELPHIA | PA |
| WANAMAKER`S – COTTMAN AVENUE | PHILADELPHIA | PA |
| WANAMIE #18 COLLIERY | WANAMIE | PA |
| WANAMIE COLLIERY | WANAMIE | PA |
| WARDEN, FREW AND COMPANY | PHILADELPHIA | PA |
| WAREN STATE BOILER HOUSE | WARREN | PA |
| Wark Army Supply | Philadelphia | PA |
| WARNER CO | DE VAULT | PA |
| WARNER CO | DEVALT | PA |
| Warner Company | Bellefonte | PA |
| WARNER COMPANY | DEVAULT | PA |
| WARNER COMPANY | PHILADELPHIA | PA |
| WARNER COMPANY – BELLEFONTE DIVISION | BELLEFONTE | PA |
| WARNER COMPANY – CEDAR HOLLOW CEMENT PLANT | DEVAULT | PA |
| WARNER COMPANY, CEDAR HOLLOW CEMENT PLANT | DEVAULT | PA |
| WARNER LAMBERT COMPANY | LITITZ | PA |
| WARNER LAMBERT LAB. | LITITZ | PA |
| WARNER LAMBERT PHARMACEUTICAL COMPANY | LITITZ | PA |
| WARREN LIGHT AND POWER COMPANY | WARREN | PA |
| Warren Power Plant (Kinzua Dam) | Warren | PA |
| WARWICK IRON AND STEEL COMPANY | POTTSTOWN | PA |
| WASHBURN AND ZERFASS | SCRANTON | PA |
| WASHBURN, WILLIAMS AND COMPANY | SERANTON | PA |
| WASHINGTON COAL AND COKE COMPANY | STAR JUNCTION | PA |
| WASHINGTON COAL AND COKE COMPANY | UNIONTOWN | PA |
| WASHINGTON CROSSING STATE PARK – MEMORIAL BUILDING | WASHINGTON CROSSING | PA |
| WASHINGTON ELECTRIC LIGHT AND POWER COMPANY – POWER PLANT | WASHINGTON | PA |
| WASHINGTON HIGH SCHOOL | LILLY | PA |
| WASHINGTON HOSPITAL | WASHINGTON | PA |
| WASHINGTON ICE COMPANY | WASHINGTON | PA |
| Washington Mold Machine & Foundry Company | Washington | PA |
| WASHINGTON POWERHOUSE | DANVILLE | PA |
| Washington Steel | Washington | PA |
| Washington Steel | Houston | PA |
| WASHINGTON STEEL AND ORDINANCE COMPANY | UNIONTOWN | PA |
| WASHINGTON STEEL AND ORDNANCE COMPANY | UNIONTOWN | PA |
| WASHINGTON TIN PLATE COMPANY | WASHINGTON | PA |
| WASHINGTON TOOL | WASHINGTON | PA |
| WASHINGTON TOOL & MACHINE CO | WASHINGTON | PA |
| Washingtonville Power Plant | Washingtonville | PA |
| WATSON LANDS LUMBER COMPANY | MAYBURG | PA |
| WATSONTOWN DOOR AND SASH COMPANY | WATSONTOWN | PA |
| WAYNE COUNTY MEMORIAL HOSPITAL | HONESDALE | PA |
| Wayne Crouse, Inc. | Butler | PA |
| WAYNE IRON WORKS | PITTSBURGH | PA |
| WAYNESBURG ELECTRIC LIGHT AND POWER COMPANY – POWER PLANT | WAYNESBURG | PA |
| WEAN UNITED | VANDERGRIFT | PA |
| Weathercraft Insulation Company | Philadelphia | PA |
| WEATHERSPOONG BUILDING, JUNIPER AND WALNUT STS. | PHILADELPHIA | PA |
| WEBSTER COAL AND COKE COMPANY | EHRENFELD | PA |
| WEBSTER COAL AND COKE COMPANY | EHRENFIELD | PA |
| WEBSTER COAL AND COKE COMPANY | PHILADELPHIA | PA |
| WEBSTER COAL AND COKE COMPANY | AMSBRY | PA |
| WEBSTER COAL AND COKE COMPANY | SCRANTON | PA |
| WEBSTER FURNACE | PHILADELPHIA | PA |
| WEEKS BROTHERS | PITTSBURGH | PA |
| WEIGHTMAN BUILDING | PHILADELPHIA | PA |
| WEIGHTMAN ESTATE | PHILADELPHIA | PA |
| WEINBERG LOUIS AND MARION | PHILADELPHIA | PA |
| WEINLS CROSSROAD STORE – 2001 GOLDEN MILE HIGHWAY ROUTE 286 | PITTSBURGH | PA |
| WEIRTON STEEL | MCKEES ROCKS | PA |
| WEIRTON STEEL – BROWNS ISLAND | MCKEES ROCKS | PA |
| Welch Grape Juice Company | North East | PA |
| WELDING ENGINEERS | NORRISTOWN | PA |
| WELLMAN-SEAVER MORGAN COMPANY | ERIE | PA |
| Wellsboro Electric Co. | Wellsboro | PA |
| WELSBACH – STATE CORRECTIONAL INST. | WHITE HAVEN | PA |
| WELSBACH – STATE CORRECTIONAL INST. – BOILER PLANT | WHITE HAVEN | PA |
| WELSH GRAPE JUICE COMPANY | NORTH EAST | PA |
| WENSTER COAL AND COKE COMPANY | AMSBRY | PA |
| WERTZ ENGINEERING CO | ALLENTOWN | PA |
| Wessell Hardware Corporation | Philadelphia | PA |
| WESSEX HOUSE APARTMENTS | ST. DAVIDS | PA |
| WEST AVE APARTMENTS | HUNTINGDON VALLEY | PA |
| West Chester Chemical | West Chester | PA |
| WEST CHESTER LAUNDRY | WEST CHESTER | PA |
| WEST CHESTER, KENNETT AND WILMINGTON ELECTRIC RAILWAY COMPANY – POWER STATION | KENNETT | PA |
| WEST END COAL COMPANY | SERANTON | PA |
| WEST END COAL COMPANY | LEE | PA |
| WEST END HEATING AND ENERGY COMPANY | PHILADELPHIA | PA |
| WEST END ROLLING MILL COMPANY | LEBANON | PA |
| WEST LEECHBURG STEEL COMPANY | LEECHBURG | PA |
| West Liberty School | Pittsburgh | PA |
| WEST NEWTON PAPER COMPANY | WEST NEWTON | PA |
| West Park Hospital | Philadelphia | PA |
| WEST PENN HOSPITAL | PITTSBURGH | PA |
| WEST PENN MOTOR CLUB BUILDING | PITTSBURGH | PA |
| West Penn Power | Courtney | PA |
| WEST PENN POWER – OFFICE BUILDING | GREENSBURG | PA |
| WEST PENN POWER CO | MILESBURG | PA |
| WEST PENN POWER CO | REESEDALE | PA |
| WEST PENN POWER CO | NEW EAGLE | PA |
| WEST PENN POWER CO – ARMSTRONG POWER STATION | KITTANNING | PA |
| WEST PENN POWER CO – ARMSTRONG POWER STATION | REESEDALE | PA |
| WEST PENN POWER CO – ARMSTRONG STATION – NEAR KITTANNING, PA. | REESEDALE | PA |
| WEST PENN POWER CO – ARMSTRONG STATION – UNIT #2 | REESEDALE | PA |
| WEST PENN POWER CO – ARMSTRONG STATION, UNIT #2 | REESEDALE | PA |
| WEST PENN POWER CO – ARMSTRONG STATION, UNIT #2 | ROSEDALE | PA |
| WEST PENN POWER CO – MITCHELL POWER STATION | MONONGAHELA | PA |
| WEST PENN POWER CO – MITCHELL POWER STATION UNIT NO 3 | COURTNEY | PA |
| WEST PENN POWER CO – MITCHELL STATION | COURTNEY | PA |
| WEST PENN POWER CO – MITCHELL STATION UNIT 3 | COURTNEY | PA |
| WEST PENN POWER CO – R. W. BIGLEY POWER STATION | SPRINGDALE | PA |
| WEST PENN POWER CO – SPRINGDALE POWER STATION UNIT #8 | SPRINGDALE | PA |
| WEST PENN POWER CO – UNIT #8 | SPRINGDALE | PA |
| WEST PENN POWER CO – UNIT & LIGHT | SPRINGDALE | PA |
| West Penn Power Co Armstrong Station | Reedsdale | PA |
| West Penn Power Co. | Greensburg | PA |
| WEST PENN POWER CO. | SPRINGDALE | PA |
| WEST PENN POWER COMPANY | SPRINGDALE | PA |
| WEST PENN POWER COMPANY | RIDGWAY | PA |
| WEST PENN POWER COMPANY | PITTSBURGH | PA |
| WEST PENN POWER COMPANY – Mitchell Station | COURTNEY | PA |
| WEST PENN POWERHOUSE | MILESBURG | PA |
| WEST PENNSYLVANIA HOSPITAL | PITTSBURGH | PA |
| WEST PENNSYLVANIA POWER COMPANY | CONNELLSVILLE | PA |
| WEST PENNSYLVANIA POWER COMPANY | COURTNEY | PA |
| WEST PENNSYLVANIA POWER COMPANY | MONONGAHELA | PA |
| WEST PENNSYLVANIA POWER COMPANY | SPRINGDALE | PA |
| WEST PENNSYLVANIA POWER COMPANY – CHESWICK STATION | CHESWICK | PA |
| WEST PENNSYLVANIA POWER COMPANY – MITCHELL STATION | COURTNEY | PA |
| WEST PENNSYLVANIA POWER COMPANY, CHESWICK STATION | CHESWICK | PA |
| WEST PENNSYLVANIA POWER COMPANY, MITCHELL POWER PLANT | COURTNEY | PA |
| WEST PENNSYLVANIA POWER COMPANY, MITCHELL STATION | COURTNEY | PA |
| WEST PENNSYLVANIA TRACTION COMPANY | CONNELLSVILLE | PA |
| WEST PENNSYLVANIA TRACTION COMPANY | BUTLER | PA |
| WEST PHILADELPHIA CITY HIGH SCHOOL – 36TH & FILBERT STREETS | PHILADELPHIA | PA |
| WEST PHILADELPHIA HIGH SCHOOL – CHESTNUT STREET | PHILADELPHIA | PA |
| WEST PHILADELPHIA STOCKYARDS | WEST PHILADELPHIA | PA |
| WEST PHILADELPHIA WORKS | PHILADELPHIA | PA |
| WEST PITTSBURGH REALTY COMPANY | WEST PITTSBURGH | PA |
| West Side School | Scranton | PA |
| WEST VIRGINIA PLATE GLASS COMPANY | PITTSBURGH | PA |
| WEST VIRGINIA POWER TRANSMISSION COMPANY | CHEAT HAVEN | PA |
| West Virginia Pulp & Paper | Tyrone | PA |
| WEST VIRGINIA PULP & PAPER CO | TYRONE | PA |
| WEST VIRGINIA PULP AND PAPER COMPANY | WILLIAMSBURG | PA |
| WEST VIRGINIA PULP AND PAPER COMPANY | TYRONE | PA |
| WESTERLY PARKWAY SCHOOL | STATE COLLEGE | PA |
| Western Electric | Reading | PA |
| WESTERN ELECTRIC CO. – BUILDING 21 | ALLENTOWN | PA |
| WESTERN ELECTRIC CO. – Repair Facility | KING OF PRUSSIA | PA |
| Western Electric Company – Allentown Works | Allentown | PA |
| Western Electric Company – Allentown Works – Building 21 | Allentown | PA |
| WESTERN ELECTRIC COMPANY – MANUFACTURING PLANT | LAURELDALE | PA |
| WESTERN ELECTRIC CORPORATION | BEAVER | PA |
| Western Metal Bed Company | Philadelphia | PA |
| WESTERN PENITENTIARY OF PENNSYLVANIA | ALLEGHENY | PA |
| WESTERN PENN | BEAVER CITY | PA |
| WESTERN PENN | PITTSBURGH | PA |
| WESTERN PENN | SHIPPINGPORT | PA |
| WESTERN PENNSYLVANIA HOSPITAL | PITTSBURGH | PA |
| WESTERN PENNSYLVANIA HOSPITAL FOR INSANE | DIXMONT | PA |
| Western Pennsylvania Power Co | Springdale | PA |
| Western Pennsylvania Power Co | Milesburg | PA |
| WESTERN STATE PSYCHIATRIC HOSPITAL | PITTSBURGH | PA |
| Western State School & Hospital | Canonsburg | PA |
| WESTFIELD RIVER PAPER CO | W. CONSCHOHOCKEN | PA |
| Westfield River Paper Co Inc | West Conshohocken | PA |
| WESTFIELD TANNING COMPANY | WESTFIELD | PA |
| Westinghouse | Lester | PA |
| Westinghouse | Sharon | PA |
| Westinghouse | Philadelphia | PA |
| Westinghouse | Shippingport | PA |
| Westinghouse | Pittsburgh | PA |
| WESTINGHOUSE | BLAIRSVILLE | PA |
| WESTINGHOUSE – ATOMIC POWER DIVISION – FOREST HILLS | PITTSBURGH | PA |
| WESTINGHOUSE – RIDGE ST WAREHOUSE | SHARON | PA |
| WESTINGHOUSE – TRAFFORD WORKS | TRAFFORD | PA |
| Westinghouse (Clairton Site) | Large | PA |
| WESTINGHOUSE AED BLDG ADDN | CHESWICK | PA |
| WESTINGHOUSE AIR | WILMERDING | PA |
| WESTINGHOUSE AIR BRAKE | WILMERDING | PA |
| Westinghouse Air Brake Co | Wilmerding | PA |
| Westinghouse Air Brake Co. | Wilmerding | PA |
| WESTINGHOUSE AIR BRAKE COMPANY | ALLEGHENY | PA |
| WESTINGHOUSE AIR BRAKE COMPANY | WILMERDING | PA |
| WESTINGHOUSE AIR BRAKE COMPANY | PITTSBURGH | PA |
| Westinghouse Atomic Labratory | West Mifflin | PA |
| WESTINGHOUSE ATOMIC POWER | HOMESTEAD | PA |
| WESTINGHOUSE ATOMIC POWER – BETTIS PLANT | WEST MIFFLIN | PA |
| Westinghouse Bettis | West Mifflin | PA |
| Westinghouse Bettis Atomic | West Mifflin | PA |
| WESTINGHOUSE BUILDING – 9th St & Penn Ave | PITTSBURGH | PA |
| WESTINGHOUSE CARS AND COMPANY | PHILADELPHIA | PA |
| WESTINGHOUSE CARS AND COMPANY | SCHENDIS FERRY | PA |
| WESTINGHOUSE ELEC CORP | LESTER | PA |
| WESTINGHOUSE ELEC CORP | E PITTSBURGH | PA |
| WESTINGHOUSE ELEC CORP | DERBY | PA |
| WESTINGHOUSE ELEC CORP | TRAFFORD | PA |
| WESTINGHOUSE ELEC CORP | DERRY | PA |
| Westinghouse Elec. Corp. | Essington | PA |
| Westinghouse Elec. Corp. | E. Pittsburgh | PA |
| WESTINGHOUSE ELECTRIC | EAST PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC – OFFICE BUILDING – NORTHERN PIKE | MONROEVILLE | PA |
| Westinghouse Electric & Manufacturing Co. | East Pittsburgh | PA |
| Westinghouse Electric & Manufacturing Co. | Irwin | PA |
| Westinghouse Electric & Manufacturing Co. | Philadelphia | PA |
| Westinghouse Electric & Manufacturing Co. | Trafford | PA |
| Westinghouse Electric & Manufacturing Co. – East Pittsburgh Works | East Pittsburgh | PA |
| WESTINGHOUSE ELECTRIC & MFG.CO | LESTER | PA |
| WESTINGHOUSE ELECTRIC AND MANUFACTURING | PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY | PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY – ALLEGHENY WORKS | ALLEGHENY | PA |
| WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY – POWER STATION | NORTH TRAFFORD | PA |
| WESTINGHOUSE ELECTRIC CO | LESTER | PA |
| WESTINGHOUSE ELECTRIC CO | BLAIRSVILLE | PA |
| WESTINGHOUSE ELECTRIC CO | LESTAR | PA |
| WESTINGHOUSE ELECTRIC CO – A B BUILDING | WILMERDING | PA |
| WESTINGHOUSE ELECTRIC CO – A.G.T. DIVISION | ESSINGTON | PA |
| WESTINGHOUSE ELECTRIC CO – ADVANCED REACTORS DIVISION | CHESWICK | PA |
| WESTINGHOUSE ELECTRIC CO – ASTRONUCLEAR LABORATORY | LARGE | PA |
| WESTINGHOUSE ELECTRIC CO – ATOMIC APPARATUS SUB DIVISION | LARGE | PA |
| WESTINGHOUSE ELECTRIC CO – ATOMIC APPARATUS SUB DIVISION – NOBLE J. DICK OFFICE BLDG. | LARGE | PA |
| WESTINGHOUSE ELECTRIC CO – BETTIS ATOMIC POWER LAB | WEST MIFFLIN | PA |
| WESTINGHOUSE ELECTRIC CO – COMMERCIAL ATOMIC POWER | EAST PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC CO – MARK J.Q. POWER PLANT | EAST PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC CO – STEAM DIVISION | ESSINGTON | PA |
| WESTINGHOUSE ELECTRIC CO – WESTINGHOUSE TURBINE – ATOMIC POWER STATION | SHIPPINGPORT | PA |
| Westinghouse Electric Company | Churchill | PA |
| Westinghouse Electric Company | Cheswick | PA |
| Westinghouse Electric Company | Monroeville | PA |
| Westinghouse Electric Company | Blairsville | PA |
| Westinghouse Electric Company | Madison | PA |
| Westinghouse Electric Company – Atomic Power Division – Forest Hills | FORREST HILLS | PA |
| Westinghouse Electric Company – Atomic Power Division – Forest Hills | West Mifflin | PA |
| Westinghouse Electric Company – Atomic Power Division – Forest Hills | PITTSBURGH | PA |
| Westinghouse Electric Company – Bettis Atomic Power Laboratory | East Pittsburgh | PA |
| Westinghouse Electric Company – Beulah Road Research & Technology Laboratory | Pittsburgh | PA |
| Westinghouse Electric Company – Churchill Research & Development Center | PITTSBURGH | PA |
| Westinghouse Electric Company – Plant | EAST PITTSBURGH | PA |
| Westinghouse Electric Company – Plant – A B Building | WILMERDING | PA |
| Westinghouse Electric Company – Plant – Mark J.Q. Power Plant | EAST PITTSBURGH | PA |
| Westinghouse Electric Company – Plant – Receiving Dept | EAST PITTSBURGH | PA |
| Westinghouse Electric Company – Plant – Section TL #12 | EAST PITTSBURGH | PA |
| Westinghouse Electric Company – Section L. Maintenance | EAST PITTSBURGH | PA |
| Westinghouse Electric Company – South Philadelphia Plant | Lester | PA |
| WESTINGHOUSE ELECTRIC COMPANY – SOUTH PHILADELPHIA WORKS | LESTER | PA |
| WESTINGHOUSE ELECTRIC COMPANY – SOUTH PHILADELPHIA WORKS – 4th floor rear | LESTER | PA |
| WESTINGHOUSE ELECTRIC COMPANY – YOUNGWOOD PLANT | YOUNGWOOD | PA |
| WESTINGHOUSE ELECTRIC COR | LESTER | PA |
| WESTINGHOUSE ELECTRIC COR | PHILADELPHIA | PA |
| WESTINGHOUSE ELECTRIC CORP | TRAFFORD | PA |
| WESTINGHOUSE ELECTRIC CORP | PHILADELPHIA | PA |
| WESTINGHOUSE ELECTRIC CORP | LESTER | PA |
| WESTINGHOUSE ELECTRIC CORP | DERRY | PA |
| WESTINGHOUSE ELECTRIC CORP | BLAIRSVILLE | PA |
| WESTINGHOUSE ELECTRIC CORP | PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC CORP | BEAVER | PA |
| WESTINGHOUSE ELECTRIC CORP | SHARON | PA |
| Westinghouse Electric Corp – Laboratory | East Pittsburgh | PA |
| Westinghouse Electric Corp – Linhart Works | Turtle Creek | PA |
| Westinghouse Electric Corp – Power House #1 | Lester | PA |
| Westinghouse Electric Corp – Specialty Metals Plant | Blairsville | PA |
| WESTINGHOUSE ELECTRIC CORP. | DERRY | PA |
| WESTINGHOUSE ELECTRIC CORP. | EAST PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC CORP. – SHARON TRANSFORMER PLANT – BOILER HOUSE | SHARON | PA |
| WESTINGHOUSE ELECTRIC CORP. – TRAFFORD WORKS | TRAFFORD | PA |
| WESTINGHOUSE ELECTRIC CORP. – TRAFFORD WORKS – BAILEY HOUSE | TRAFFORD | PA |
| Westinghouse Electric Corporation | Blairsville | PA |
| WESTINGHOUSE ELECTRIC CORPORATION | BEAVER | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – BEAVER PLANT | BEAVER | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – DERRY WORKS | DERRY | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – EAST PITTSBURGH WORKS | EAST PITTSBURGH | PA |
| Westinghouse Electric Corporation – Keystone Power Station | Elderton | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – KEYSTONE STATION | ELDERTON | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – KEYSTONE STATION – UNITS #1 & #2 – ARMSTRONG COUNTY | SHELOCTA | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – MICA-PROCESSING PLANT | IRWIN | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – RESEARCH & DEVEL. CENTER – BEULAH ROAD | PITTSBURGH | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – SHARON PLANT | SHARON | PA |
| WESTINGHOUSE ELECTRIC CORPORATION – WALTZ MILL PLANT | MADISON | PA |
| WESTINGHOUSE ELECTRIC PLANT | Greensburg | PA |
| WESTINGHOUSE ELECTRIC, RESEARCH LAB | PITTSBURGH | PA |
| WESTINGHOUSE ELECTRO CO – WESTINGHOUSE ASTRONUCLEAR LABORATORY | LARGE | PA |
| WESTINGHOUSE GENERAL ELECTRIC AND MANUFACTURING COMPANY | PITTSBURGH | PA |
| WESTINGHOUSE HIGH VOLTAGE INSULATOR COMPANY | DERRY | PA |
| Westinghouse Industrial Furnace | Meadville | PA |
| WESTINGHOUSE PLANT | EAST PITTSBURGH | PA |
| WESTINGHOUSE POWER DIVISION – CLAIRTON SITE | LARGE | PA |
| WESTINGHOUSE STEAM DIVISION | LESTER | PA |
| WESTINGHOUSE, CHURCH, KERR AND COMPANY | COOKS FERRY | PA |
| WESTLAND MINE | WESTLAND | PA |
| WESTMINSTER COLLEGE – HOYT SCIENCE RESOURCES CENTER | NEW WILMINGTON | PA |
| WESTMORELAND COAL COMPANY | IRWIN | PA |
| WESTMORELAND COAL COMPANY | YUKON | PA |
| WESTMORELAND COAL COMPANY | RILLTON | PA |
| WESTMORELAND COUNTY HOME FOR THE DESTITUTE | GREENSBURG | PA |
| WESTMORELAND HOSPITAL | GREENSBURG | PA |
| WESTMORELAND PAPER COMPANY | WEST NEWTON | PA |
| Westmoreland Water Company | Derry | PA |
| Weston Field | Scranton | PA |
| WESTSIDE OSTEOPATHIC HOSPITAL | YORK | PA |
| Westvaco | Williamsburg | PA |
| Westvaco Corp. | Tyrone | PA |
| WESTVACO CORPORATION | TYRONE | PA |
| Westvaco Pulp And Paper | Tyrone | PA |
| Weyerhaeuser Co | Minquon | PA |
| WEYERHAEUSER COMPANY | RIDGWAY | PA |
| Weyeth Laboratories, Inc. | Malvern | PA |
| Weyeth Laboratories, Inc. | West Chester | PA |
| WHEATLAND TUBE | WHEATLAND | PA |
| WHEELABRATOR FALLS WTE | MORRISVILLE | PA |
| Wheeling Pitt Steel | MONESSEN | PA |
| WHEELING PITTSBURGH MONESSEN | MONESSEN | PA |
| Wheeling Pittsburgh Steel | Allenport | PA |
| Wheeling Pittsburgh Steel | Monessen | PA |
| WHEELING PITTSBURGH STEEL | PITTSBURGH | PA |
| WHEELING PITTSBURGH STEEL CORP | MONESSEN | PA |
| Wheeling Pittsburgh Steel Products | Allenport | PA |
| Wheeling-Pittsburg Steel Corporation | Allenport | PA |
| Wheeling-Pittsburgh Steel | Monessen | PA |
| Wheeling-Pittsburgh Steel | Allenport | PA |
| Wheeling-Pittsburgh Steel Corporation | Monessen | PA |
| WHEELING-PITTSBURGH STEEL CORPORATION | ALLENPORT | PA |
| WHEELWRIGHT AND MUDGE | YORK | PA |
| WHITE MOUNTAIN PAPER COMPANY | PORTSMOUTH | PA |
| WHITE PIGMENT CORPORATION | KING OF PRUSSIA | PA |
| WHITEHALL CEMENT CO | CEMENTON | PA |
| Whitehall Cement Co. | Annville | PA |
| WHITEHALL CEMENT CO. | CEMENTON | PA |
| WHITEHALL CEMENT MFG. CO | CEMENTON | PA |
| WHITEHALL PORTLAND CEMENT COMPANY | CEMENTON | PA |
| WHITEHAVEN SANATORIUM | WHITE HAVEN | PA |
| WHITEMARSH TOWNSHIP | MONTGOMERY COUNTY | PA |
| WHITEMARSH TOWNSHIP INC | LAFAYETTE HILL | PA |
| WHITEMARSH TOWNSHIP INCINERATOR | LAFAYETTE HILL | PA |
| Whiting Corporation | Erie | PA |
| WHITMAN CHOCOLATE | PHILADELPHIA | PA |
| WHITMARSH TOWNSHIP INCINERATOR | LAFAYETTE | PA |
| Whitmoyer Laboratories | Myerstown | PA |
| WIDENER BUILDING | PHILADELPHIA | PA |
| WIEGNER SMELTING CO | PHILADELPHIA | PA |
| WILBUR CHOCOLATE COMPANY | PHILADELPHIA | PA |
| Wilcox Wilford Corp | Royersford | PA |
| Wilcox Wilford Corp | Spring City | PA |
| Wildman & Schwartz | Norristown | PA |
| WILDMAN ARMS APARTMENTS | LANDSOWNE | PA |
| WILDMAN JACQUARD COMPANY | NORRISTOWN | PA |
| WILDMAN JAQUARD COMPANY | NORRISTOWN | PA |
| WILIAMSPORT – STATION | MIDDLEBURG | PENNSYLVANIA |
| WILKES BARRE ANTHRACITE COAL COMPANY | WILKES BARRE | PA |
| WILKES BARRE COMPANY | WILKES BARRE | PA |
| WILKES BARRE ELECTRIC LIGHT COMPANY – POWER PLANT | WILKES BARRE | PA |
| WILKES BARRE STEAM HEAT COMPANY – POWER PLANT | WILKES BARRE | PA |
| WILKESBARRE RAILWAY COMPANY | WILKES BARRE | PA |
| WILKES-BARRE/SCRANTON INTERNATIONAL AIRPORT – SECOND TERMINAL BUILDING | AVOCA | PA |
| WILKINSBURG AND EAST PITTSBURGH RAILROAD | PITTSBURGH | PA |
| WILKINSBURG ELECTRIC COMPANY – POWER PLANT | WILKINSBURG | PA |
| WILKINSBURG HIGH SCHOOL | WILKINSBURG | PA |
| WILKINSON AND EAST PITTSBURGH STREET RAILWAY COMPANY | PITTSBURGH | PA |
| WILKINSON AND EAST PITTSBURGH STREET RAILWAY COMPANY | RANKIN | PA |
| WILLAMETTE INDUSTRIES | JOHNSONBURG | PA |
| William A Mc Dowell Jr Co | Philadelphia | PA |
| WILLIAM A. SHOEMAKER SCHOOL | MACUNGIE | PA |
| WILLIAM ARMSTRONG & SONS | CONSHOHOCKEN | PA |
| WILLIAM ARMSTRONG & SONS | PHILADELPHIA | PA |
| WILLIAM ARMSTRONG & SONS, PHIL ELLENA AND CHEW STS. | GERMANTOWN | PA |
| William Cramp and Sons | Philadelphia | PA |
| WILLIAM CRAMP AND SONS SHIP AND ENGINE BUILDING COMPANY | PHILADELPHIA | PA |
| WILLIAM CRAMP AND SONS, SHIP ENGINE BUILDING COMPANY | PHILADELPHIA | PA |
| WILLIAM F. FOREPAUGH JR. AND BRO. | PHILADELPHIA | PA |
| WILLIAM GALLOWAY | PHILADELPHIA | PA |
| WILLIAM H. GRUNDY AND COMPANY | BRISTOL | PA |
| William H. Ottemiller Co. | York | PA |
| WILLIAM H. TAYLOR AND COMPANY | ALLENTOWN | PA |
| WILLIAM J. MIMM LANCASTER FLOOR PLANT | LANCASTER | PA |
| WILLIAM J. MIMM LANCASTER FLOOR PLANT – REACTION KETTLE BLDG #56- 4 | LANCASTER | PA |
| WILLIAM KRAUSE AND SONS CEMENT COMPANY | MARTINS CREEK | PA |
| WILLIAM L. SAYRE JUNIOR HIGH SCHOOL | PHILADELPHIA | PA |
| WILLIAM LEARD COMPANY | NEW BRIGHTON | PA |
| WILLIAM LOESCHE – ELEMENTARY SCHOOL | PHILADELPHIA | PA |
| WILLIAM MANN COMPANY | PHILADELPHIA | PA |
| WILLIAM MILLER AND SONS COMPANY | PITTSBURGH | PA |
| WILLIAM PENN APARTMENTS | PHILADELPHIA | PA |
| WILLIAM PENN COLLIERY | SHENANDOAH | PA |
| WILLIAM PENN HIGH SCHOOL | PHILADELPHIA | PA |
| WILLIAM PENN HOTEL | PITTSBURGH | PA |
| WILLIAM PENN P.O. | LAFAYETTE | PA |
| WILLIAM PENN P.O. | MONTGOMERY COUNTY | PA |
| WILLIAM STEELE SONS COMPANY | PHILADELPHIA | PA |
| WILLIAM WEIGHTMAN | PHILADELPHIA | PA |
| WILLIAM WEIGHTMAN BUILDING | PHILADELPHIA | PA |
| WILLIAM WEIGHTMAN, BINGHAM HOUSE | PHILADELPHIA | PA |
| William Wharton | Easton | PA |
| WILLIAM WHARTON JR. COMPANY | EASTON | PA |
| WILLIAM WHITAKER & SONS | PHILADELPHIA | PA |
| WILLIAM WHITAKER AND SONS | PHILADELPHIA | PA |
| Williamsburg Generating Station | Williamsburg | PA |
| WILLIAMSGROVE CLAY PRODUCTS | BIGLER | PA |
| WILLIAMSON BROTHERS COMPANY | PHILADELPHIA | PA |
| WILLIAMSON TRADE SCHOOL | MEDIA | PA |
| WILLIAMSPORT | WILLIAMSPORT | PENNSYLVANIA |
| WILLIAMSPORT FREE SCHOOL OF MECHANICAL TRADES | MEDIA | PA |
| WILLIAMSPORT HOSPITAL – HIGH STREET | WILLIAMSPORT | PA |
| Williamsport Powerhouse | Williamsport | PA |
| Williamsport Technical Institute | Williamsport | PA |
| Williard Inc | King Of Prussia | PA |
| Willowbrook # 3 | Plymouth Meeting | PA |
| WILLSON PRODUCTS DIVISION | READING | PA |
| WILMINGTON CHEMICAL PLANT | PHILADELPHIA | PA |
| WILPUTTE COKE OVEN, DIVISION OF ALLIED CHEMICAL CORPORATION | PHILADELPHIA | PA |
| WILSON & COMPANY | SUNBURY | PA |
| WILSON AND COMPANY, INCORPORATED | PHILADELPHIA | PA |
| Wilson Fitzgibbons Oil Company | Bradford | PA |
| WILSON H. BROWN, INCORPORATED | GERMANTOWN | PA |
| WILSON MARTIN CO.,INC. | PHILADELPHIA | PA |
| WILSON MARTIN CO.,INC. – WILSON MARTIN DIV. | PHILADELPHIA | PA |
| WILSON MARTIN COMPANY | PHILADELPHIA | PA |
| Wilson Park Apartments | Philadelphia | PA |
| Wilson Safety Products | Reading | PA |
| WILSON SENIOR HIGH SCHOOL | SINKING SPRINGS | PA |
| WILSON SNYDER BUILDING | PITTSBURGH | PA |
| WILSON-SNYDER CENTRIFUGAL PUMP COMPANY | PITTSBURGH | PA |
| WINCHESTER APARTMENTS – NEVILLE ROAD | OAKLAND | PA |
| WINDBER ELECTRIC COMPANY – POWER PLANT | WINDBER | PA |
| WINTER BREWERY | PITTSBURGH | PA |
| WINTERSET APARTMENTS – 800 STRATFORD DRIVE | STATE COLLEGE | PA |
| WIRE MILL | JOHNSTOWN | PA |
| WIRTZ A H INC | CHESTER | PA |
| WISE | KINGSTON | PA |
| Wise Delicatessen Company | Berwick | PA |
| Wise Foods | Berwick | PA |
| WISE FOODS INC | BERWICK | PA |
| WISE POTATO CHIP CO | BURWICK | PA |
| WISE POTATOE CHIP CO | BERWICK | PA |
| Wishart Theatre | Philadelphia | PA |
| WITCO CHEMICAL CO | PETROLIA | PA |
| WITCO CHEMICAL COMPANY, INCORPORATED | PETROLIA | PA |
| WITCO CHEMICAL CORP | BRADFORD | PA |
| Witco Chemical Corp. | Bradford | PA |
| WITCO CHEMICAL CORPORATION | PETROLIA | PA |
| WITCO CHEMICAL CORPORATION ACTIVATED CARBON DIVISION | PETROLIA | PA |
| WITCO CHEMICAL PLANT | MARKUS HOOK | PA |
| WITCO CHEMICAL SONNEBORN DIVISION | PETROLIA | PA |
| WITCO CORPORATION | PETROLIA | PA |
| Wm A Mc Dowell Jr Co | Philadelphia | PA |
| WMCA Radio Station | Chambersburg | PA |
| WOLF BUILDING COMPANY | PHILADELPHIA | PA |
| WOLFS HEAD OIL REFG CO (a/k/a Wolverine Empire Refinishing Co.) | RENO | PA |
| WOLF’S HEAD OIL REFINING COMPANY, INCORPORATED | RENO | PA |
| WOLFS HEAD REFINING COMPANY | RENO | PA |
| WOMEN`S MEDICAL COLLEGE HOSPITAL – HENRY AVENUE | PHILADELPHIA | PA |
| WOMEN’S CHRISTIAN ASSOCIATION | PHILADELPHIA | PA |
| WOOD JOHN CO | CONSHOHOCKEN | PA |
| WOOD MRS JOSEPHINE GREEN | CONSHOHOCKEN | PA |
| WOOD, ALAN, STEEL COMPANY | CONSHOHOCKEN | PA |
| WOODBOURNE APARTMENT ASSOCIATION | LEVITTOWN | PA |
| WOODINGS ROBERT T INC | PITTSBURGH | PA |
| WOODINGS VERONA STEEL WORKS | VERONA | PA |
| WOODINGS VERONA TOOL WORK | VERONA | PA |
| WOODINGS VERONA TOOL WORKS | VERONA | PA |
| WOODINGS VERONA TOOLS WORKS | VERONA | PA |
| WOODINGS VERONA TOOLWORK | VERONA | PA |
| WOODLAND FIRE BRICK COMPANY | WOODLAND | PA |
| WOOLWORTH BUILDING | LANCASTER | PA |
| WORKS #1 | CREIGHTON | PA |
| WORTH BROTHERS COMPANY | COATESVILLE | PA |
| WRIGHT BROTHERS AND COMPANY | PHILADELPHIA | PA |
| WRIGHT ELEMENTARY SCHOOL | ALTOONA | PA |
| WV Pulp & Paper Company | Tyrone | PA |
| Wycoff Steel | Ambridge | PA |
| Wyeth Laboratories | Malvern | PA |
| WYETH LABORATORIES INC | PAOLI | PA |
| WYETH LABS | MALVERN | PA |
| WYETH LABS | PHILADELPHIA | PA |
| WYETH LABS | WEST CHESTER | PA |
| WYOMING AVE AND G ST. | PHILADELPHIA | PA |
| WYOMING ENGINEERING COMPANY | WILKES BARRE | PA |
| WYOMING VALLEY ELECTRIC LIGHT, HEAT & POWER COMPANY – POWER PLANT | WILKES BARRE | PA |
| YERKS AND PLUMB | FRANKFORD | PA |
| YEWDALL AND JONES BROTHERS | PHILADELPHIA | PA |
| YMCA | PHILADELPHIA | PA |
| YMCA | LANSDALE | PA |
| YMCA | POTTSTOWN | PA |
| YMCA – EAST BROAD STREET | BETHLEHEM | PA |
| YMCA – WASHINGTON STREET | READING | PA |
| YMCA Auditorium | Ridgeway | PA |
| YMCA BLDG | LANCASTER | PA |
| YMHA | Philadelphia | PA |
| YODER INDUSTRIES | YORK | PA |
| YORK CORP | YORK | PA |
| York Corporation | York | PA |
| York Corrugating Company | York | PA |
| York County Courthouse | York | PA |
| York Hospital | York | PA |
| YORK INTERNATIONAL CORPORATION | YORK | PA |
| YORK JUNIOR COLLEGE – LIBRARY | YORK | PA |
| YORK MANUFACTURING COMPANY | YORK | PA |
| York Shipley Inc | York | PA |
| York Water Co. | York | PA |
| YORKHAVEN PAPER COMPANY | YORK HAVEN | PA |
| Yorktown Theatre | Ogonty | PA |
| YORKTOWNE HOTEL | YORK | PA |
| YOUNG DOOR COMPANY | SUNBURY | PA |
| YOUNG EVERETT | KINZERS | PA |
| YOUNGSTOWN SHEET & TUBE CO | MCKEES ROCKS | PA |
| Youngstown Sheet & Tube Co. | Coraopolis | PA |
| Z & L Lumber Co | Burgettstown | PA |
| Z & L Lumber Co | Mercer | PA |
| Z & L Lumber Co | Sharpsburg | PA |
| ZABEL BROS. CO. INC | PHILADELPHIA | PA |
| ZACK INDUSTRIES | READING | PA |
| Zausner Foods Corp | New Holland | PA |
| ZEDMARK, INC. | VALENCIA | PA |
| ZENITH CORPORATION | LANSDALE | PA |
| ZENITH MANUFACTURING PLANT | NORTH WALES | PA |
| ZINC SMELTING DIVISION | MONACA | PA |
| ZINMAN FURS | PHILADELPHIA | PA |
| ZION INDUSTRIES | BRADFORD | PA |
| Zion Lutheran Church | Penbrook | PA |
| Zonolite Company | New Castle | PA |
| ZUG AND COMPANY, LIMITED | PITTSBURGH | PA |
| ZUG IRON AND STEEL COMPANY | PITTSBURGH | PA |
| ZURN INDUSTRIES | ERIE | PA |
| Zurn Industries Inc. | Erie | PA |
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