| 501 | Oil & Gas SVC Inc | Reelsville, IN 46171-9686 | Gas Operator | Dec 1991 |
| 502 | Oil Creek Operators LLC | Franklin, PA 16323 | Oil Operator | Dec 2025 |
| 503 | Old MTN Gas Co Inc | Pleasantville, PA 16341-0329 | Oil & Gas Operator | Dec 2020 |
| 504 | Olympus Energy, LLC | Canonsburg, PA 15317-7536 | Gas Operator | Jun 2025 |
| 505 | Olympus Prop Inc | Franklin Park, IL 60131-1418 | Oil & Gas Operator | Dec 1997 |
| 506 | Onexxx Prod & Exploration Corp | Jeannette, PA 15644-9691 | Gas Operator | Dec 2025 |
| 507 | Open Flow Gas Supply Corp | Du Bois, PA 15801-2442 | Oil & Gas Operator | Dec 2025 |
| 508 | Otter Exploration Inc | Warren, PA 16365-9689 | Oil & Gas Operator | Dec 2021 |
| 509 | Ows Acquisition Co LLC | Louisville, OH 44641 | Oil & Gas Operator | Dec 2025 |
| 510 | Ows Energy LLC | Carlton, PA 16311-1605 | Oil & Gas Operator | Mar 2026 |
| 511 | Oz Gas LTD | Tidioute, PA 16351-2648 | Oil & Gas Operator | Dec 2016 |
| 512 | P & C Energy Co | Allegany, NY 14706-9615 | Oil Operator | Dec 2015 |
| 513 | Pa DCNR State Parks Bur | Harrisburg, PA 17105-8551 | Gas Operator | Dec 2025 |
| 514 | Pa Dep Ofc Oil & Gas MGMT | Harrisburg, PA 17105-8765 | Gas Operator | Dec 1990 |
| 515 | Pa Gen Energy Co LLC | Warren, PA 16365-2510 | Oil & Gas Operator | Mar 2026 |
| 516 | Pa Gen Energy Corp | Warren, PA 16365-2510 | Oil & Gas Operator | Dec 2002 |
| 517 | Pa Land Holdings Corp | Waynesburg, PA 15370-3020 | Oil & Gas Operator | Dec 2011 |
| 518 | Pa Mineral SVCS LLC | Indiana, PA 15701 | Oil & Gas Operator | Dec 2025 |
| 519 | Pa Prod SVC Inc | Indiana, PA 15701-0421 | Oil & Gas Operator | Dec 2025 |
| 520 | Pa State Sys Of Higher Ed Indiana Univ | Indiana, PA 15705-0001 | Gas Operator | Dec 2012 |
| 521 | Papesch Robert J | Waterford, PA 16441-4607 | Gas Operator | Dec 2025 |
| 522 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 523 | Patalon Robert E | Erie, PA 16505-0444 | Gas Operator | Dec 2025 |
| 524 | Patrick Shipley | Indiana, PA 15701-6501 | Oil & Gas Operator | Dec 2016 |
| 525 | Patriot Exploration Corp | Stahlstown, PA 15687-1301 | Oil & Gas Operator | Dec 2025 |
| 526 | PDC Mountaineer LLC | Bridgeport, WV 26330-9665 | Oil & Gas Operator | Dec 2017 |
| 527 | Peak Energy LLC | Coffeyville, KS 67337 | Oil & Gas Operator | Dec 2025 |
| 528 | Pecora Enterprises | Bradford, PA 16701-1026 | Oil & Gas Operator | Dec 1999 |
| 529 | Peggy J Bell | Sheffield, PA 16347-0776 | Oil & Gas Operator | Dec 2004 |
| 530 | Pembrooke Oil & Gas Inc | Franklin, PA 16323-7760 | Oil & Gas Operator | Dec 2025 |
| 531 | Pemco Gas Inc | Indian Harbor B, FL 32937 | Oil & Gas Operator | Dec 1997 |
| 532 | Penn VIew Exploration Inc | Blairsville, PA 15717-7961 | Oil & Gas Operator | Mar 2026 |
| 533 | Penn VIrginia Oil & Gas Corp | Houston, TX 77024 | Oil & Gas Operator | Dec 2023 |
| 534 | Penneco Oil Company, Inc. | Delmont, PA 15626-2408 | Oil & Gas Operator | Dec 2025 |
| 535 | Pennenergy Resources LLC | Pittsburgh, PA 15275-1063 | Oil & Gas Operator | Mar 2026 |
| 536 | Pennfield Energy LLC | Erie, PA 16510-4760 | Oil & Gas Operator | Dec 2021 |
| 537 | Pennhills Resources LLC | MT. Jewett, PA 16740 | Oil & Gas Operator | Mar 2026 |
| 538 | Pennzoil Prod Co | Vienna, WV 26105-2141 | Oil & Gas Operator | Dec 2000 |
| 539 | Pentex Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 540 | Peoples Gas Co LLC | Butler, PA 16001-4904 | Oil & Gas Operator | Dec 2005 |
| 541 | Peoples Natural Gas Co LLC | Pittsburgh, PA 15212 | Gas Operator | Dec 2016 |
| 542 | Petro Dev Corp | Bridgeport, WV 26330-0026 | Oil & Gas Operator | Dec 2013 |
| 543 | Petro North LTD | Smethport, PA 16749-0742 | Oil & Gas Operator | Dec 2025 |
| 544 | Petro SVC Partners Inc | Indiana, PA 15701-8556 | Oil & Gas Operator | Dec 2025 |
| 545 | Petro Ventures Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2019 |
| 546 | Petrobank Opr Co | Denver, CO 80202-4675 | Gas Operator | Dec 1992 |
| 547 | Phillips Exploration Inc | Warrendale, PA 15086 | Oil & Gas Operator | Dec 2012 |
| 548 | Phillips Prod Co | Warrendale, PA 15086-7537 | Oil & Gas Operator | Dec 2011 |
| 549 | Phoenix Energy LLC | Warren, PA 16365-2302 | Oil & Gas Operator | Dec 2025 |
| 550 | Phoenix Energy Prod Inc | Freeport, PA 16229-1126 | Oil & Gas Operator | Dec 2025 |
| 551 | Pierce & Petersen | Warren, PA 16365 | Oil & Gas Operator | Dec 2025 |
| 552 | Pierce James E | Warren, PA 16365-0627 | Oil & Gas Operator | Dec 2011 |
| 553 | Pillar Energy Pa LLC | Charleston, WV 25312-5987 | Oil & Gas Operator | Dec 2025 |
| 554 | Pin Oak Energy Partners LLC | Akron, OH 44311 | Oil & Gas Operator | Mar 2026 |
| 555 | Pine City Gas LLC | Lucinda, PA 16235-0060 | Oil & Gas Operator | Dec 2025 |
| 556 | Pine Ridge Energy | Sugar Grove, PA 16350-6934 | Oil & Gas Operator | Dec 2025 |
| 557 | Pine Valley Resources Inc | West Seneca, NY 14224-2244 | Oil & Gas Operator | Dec 1991 |
| 558 | Plants & Goodwin Inc | Bradford, PA 16701-3733 | Oil & Gas Operator | Dec 2018 |
| 559 | Pleasant Oil & Gas | Clarendon, PA 16313-4532 | Oil & Gas Operator | Dec 2025 |
| 560 | PNB Petrol Haddad & Brooks Inc | Atlanta, GA 30305-1555 | Oil & Gas Operator | Dec 1989 |
| 561 | Port Erie Plastics Inc | Harborcreek, PA 16421-1018 | Gas Operator | Dec 2025 |
| 562 | Potter McKean Resources Of Pa | Shinglehouse, PA 16748-2631 | Gas Operator | Dec 2007 |
| 563 | Powder Mill Gas Co | New Bethlehem, PA 16242-2252 | Oil & Gas Operator | Dec 2025 |
| 564 | Powell Donovan L | Spraggs, PA 15362-2019 | Gas Operator | Dec 2025 |
| 565 | Power Gas MKT & Trans Inc | Akron, OH 44311-1062 | Oil & Gas Operator | Dec 2008 |
| 566 | PPG Oper LLC | State College, PA 16801-7569 | Gas Operator | Mar 2026 |
| 567 | PPP Future Dev Inc | Alexander, NY 14005 | Oil & Gas Operator | Dec 2025 |
| 568 | Puma Energy Inc | | Gas Operator | Dec 1999 |
| 569 | Pve Oil Corp Inc | Blairsville, PA 15717-7961 | Oil & Gas Operator | Dec 2025 |
| 570 | Quail Energy Corp | MT Gilead, OH 43338 | Oil & Gas Operator | Dec 2010 |
| 571 | Quaker State Corporation | Houston, TX 77002-2806 | Oil & Gas Operator | Dec 2013 |
| 572 | Questa Petro Co | Pittsburgh, PA 15241-0863 | Oil & Gas Operator | Dec 2023 |
| 573 | R & N Resources LLC | Bear Lake, PA 16402-2926 | Oil & Gas Operator | Dec 2025 |
| 574 | R & R Oil & Gas LLC | Big Spring, TX 79720 | Oil & Gas Operator | Dec 2025 |
| 575 | R B Robertson & Son Gas & Oil Co LP | New Bethlehem, PA 16242-0190 | Oil & Gas Operator | Dec 2024 |
| 576 | R Harris Gas & Oil Inc | Apollo, PA 15613-9636 | Oil & Gas Operator | Dec 2025 |
| 577 | R Joseph & Shelby J Maney | Warren, PA 16365-3670 | Oil & Gas Operator | Dec 2025 |
| 578 | Rabbitt C Michael | Chicora, PA 16025-1916 | Oil & Gas Operator | Dec 2015 |
| 579 | Ralph L Albright Drilling | Reno, NV 89511-7627 | Oil & Gas Operator | Dec 1991 |
| 580 | Randall Florence | Albion, PA 16401-9768 | Gas Operator | Dec 2010 |
| 581 | Range Opr Co | Yatesboro, PA 16263-0235 | Oil & Gas Operator | Dec 1999 |
| 582 | Range Resources Appalachia LLC | Canonsburg, PA 15317 | Oil & Gas Operator | Mar 2026 |
| 583 | Rannuff Oil & Gas Co | Waynesburg, PA 15370-1437 | Oil & Gas Operator | Dec 2025 |
| 584 | RC Southwell Oil LLC | Warren, PA 16365-3686 | Oil & Gas Operator | Dec 2025 |
| 585 | Re Fox & Assoc Inc | Pittsburgh, PA 15243-0130 | Gas Operator | Dec 1999 |
| 586 | Re Gas Dev LLC | State College, PA 16801-7085 | Oil & Gas Operator | Sep 2018 |
| 587 | Reclusive Energy LLC | Gifford, PA 16732 | Oil & Gas Operator | Dec 2020 |
| 588 | Red Jacket Energy LLC | Roulette, PA 16746-1408 | Oil & Gas Operator | Dec 2024 |
| 589 | Red Oak Energy LLC | Clarksburg, PA 15725-8824 | Oil & Gas Operator | Dec 2025 |
| 590 | Red Valley Resources LLC | McCordsville, IN 46055-0294 | Oil Operator | Dec 2015 |
| 591 | Redmill Drilling | Kittanning, PA 16201-7123 | Oil & Gas Operator | Mar 2026 |
| 592 | Rejiss Assoc | Braddock, PA 15104-1948 | Oil & Gas Operator | Dec 2009 |
| 593 | Rejiss Assoc Holdings LLC | Braddock, PA 15104-1948 | Gas Operator | Dec 2025 |
| 594 | Remington Capital Holdings Inc | North East, PA 16428-0026 | Oil & Gas Operator | Dec 2022 |
| 595 | Remnant Group Inc | Pittsburgh, PA 15238-1359 | Oil & Gas Operator | Dec 2013 |
| 596 | Rensma Steven E | Titusville, PA 16354-5304 | Oil Operator | Dec 1993 |
| 597 | Repsol Oil & Gas USA, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jun 2026 |
| 598 | Return Oil Corp | Oil City, PA 16301-0564 | Oil Operator | Dec 1992 |
| 599 | Rex Drummond | Conneaut, OH 44030-9678 | Oil & Gas Operator | Dec 2019 |
| 600 | Rex Energy Operating Corp. | State College, PA 16801 | Oil & Gas Operator | Jun 2012 |