| 501 | Millennium Oil & Gas Inc | Dexter, KS 67038 | Oil & Gas Operator | Dec 2024 |
| 502 | Minard Run Oil Co | Bradford, PA 16701 | Oil & Gas Operator | Dec 2024 |
| 503 | Minteer & Baker Gas Enterprise | Kittanning, PA 16201-5022 | Gas Operator | Dec 2024 |
| 504 | Minter Lee M | Bradford, PA 16701-3763 | Gas Operator | Dec 1991 |
| 505 | Missing Moon Oil Inc | Knox, PA 16232-4507 | Oil & Gas Operator | Dec 2024 |
| 506 | Mitch Well Energy Inc | Waterford, PA 16441-8143 | Oil & Gas Operator | Dec 2012 |
| 507 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 508 | Mob Corp | Waynesburg, PA 15370-2036 | Gas Operator | Dec 2007 |
| 509 | Monona LLC | Ligonier, PA 15658-0612 | Gas Operator | Sep 2025 |
| 510 | Monroe Res LTD | Fairport, NY 14450-3218 | Gas Operator | Dec 2004 |
| 511 | Mount Chestnut Dev LLC | Butler, PA 16002-3940 | Gas Operator | Dec 2017 |
| 512 | MSL Oil & Gas Corp | Bradford, PA 16701-0151 | Oil & Gas Operator | Dec 2024 |
| 513 | MT Savage Refractories | Pittsburgh, PA 15206-0171 | Gas Operator | Dec 2021 |
| 514 | MTN Energy | Aleppo, PA 15310 | Oil & Gas Operator | Sep 2025 |
| 515 | MTN V Oil & Gas Inc | Indiana, PA 15701-8914 | Oil & Gas Operator | Sep 2025 |
| 516 | Murphy Prod Inc | Vanderbilt, PA 15486-1001 | Oil & Gas Operator | Dec 2024 |
| 517 | Mutual Oil & Gas Co | Akron, OH 44311 | Oil & Gas Operator | Dec 2000 |
| 518 | Natl Fuel Gas Supply Corp | Williamsville, NY 14221-5887 | Oil & Gas Operator | Dec 2009 |
| 519 | Natural Energy Dev Corp | Pittsburgh, PA 15241-1548 | Oil & Gas Operator | Dec 2018 |
| 520 | Natural Oil & Gas Corp | Bradford, PA 16701 | Oil & Gas Operator | Dec 2023 |
| 521 | NCL Natural Resources LLC | Spring, TX 77381-5261 | Oil & Gas Operator | Dec 2017 |
| 522 | Nea Cross Inc | Erie, PA 16508-2769 | Gas Operator | Dec 1991 |
| 523 | New Century Energy Inc | MC Donald, PA 15057-2163 | Oil & Gas Operator | Dec 2021 |
| 524 | New York Natural Gas Corp | Pittsburgh, PA 15222-1402 | Gas Operator | Dec 1990 |
| 525 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Dec 2025 |
| 526 | Norbert J Baumgart | Warren, PA 16365-3403 | Oil & Gas Operator | Dec 2009 |
| 527 | Nornew Inc | Houston, TX 77063-2140 | Oil & Gas Operator | Dec 2008 |
| 528 | North Amer Oil & Gas Drilling Co Inc | Pleasantville, PA 16341-0197 | Oil Operator | Dec 1999 |
| 529 | North Cambria Fuel Co | Blairsville, PA 15717-7961 | Gas Operator | Dec 2008 |
| 530 | North East Gas & Oil Co | Scottsville, VA 24590-3962 | Oil & Gas Operator | Dec 2013 |
| 531 | North John M | Valatie, NY 12184-5005 | Gas Operator | Dec 2014 |
| 532 | North Penn Gas Co | Allentown, PA 18101-1139 | Gas Operator | Dec 2000 |
| 533 | North Star Energy Resources LLC | Waynesburg, PA 15370-3833 | Gas Operator | Dec 2024 |
| 534 | Northeast Natural Energy LLC | Charleston, WV 25301-2719 | Oil & Gas Operator | Sep 2025 |
| 535 | Northeastern Opr Co Inc | Shelocta, PA 15774-2346 | Gas Operator | Dec 2024 |
| 536 | Northwest Natural Gas Co | Albion, PA 16401-9998 | Oil & Gas Operator | Dec 1990 |
| 537 | Northwestern Inc | East Brady, PA 16028 | Gas Operator | Dec 2012 |
| 538 | Noumenon Corporation | Core, WV 26541-7072 | Oil & Gas Operator | Dec 2024 |
| 539 | NTS Energy LLC | Indiana, PA 15701-1801 | Oil & Gas Operator | Dec 2015 |
| 540 | Nucomer Energy LLC | Erie, PA 16510 | Oil & Gas Operator | Sep 2025 |
| 541 | Nys Natural Gas Co | Englewood, CO 80111-4737 | Gas Operator | Dec 1984 |
| 542 | Nytis Exploration Company LLC | Lexington, KY 40509 | Oil & Gas Operator | Dec 2021 |
| 543 | Oakes Gas Co Inc | Kane, PA 16735-3905 | Gas Operator | Dec 2023 |
| 544 | Oakmont CC | Oakmont, PA 15139-1135 | Gas Operator | Dec 2024 |
| 545 | Ohio Kentucky Oil Corporation | Lexington, KY 40503 | Oil & Gas Operator | Dec 2023 |
| 546 | Oil & Gas MGMT Inc | Mount Pleasant, PA 15666-3304 | Oil & Gas Operator | Dec 2024 |
| 547 | Oil & Gas SVC Inc | Reelsville, IN 46171-9686 | Gas Operator | Dec 1991 |
| 548 | Old MTN Gas Co Inc | Pleasantville, PA 16341-0329 | Oil & Gas Operator | Dec 2020 |
| 549 | Olympus Energy, LLC | Canonsburg, PA 15317-7536 | Gas Operator | Jun 2025 |
| 550 | Olympus Prop Inc | Franklin Park, IL 60131-1418 | Oil & Gas Operator | Dec 1997 |
| 551 | Onexxx Prod & Exploration Corp | Jeannette, PA 15644-9691 | Gas Operator | Dec 2024 |
| 552 | Open Flow Gas Supply Corp | Du Bois, PA 15801-2442 | Oil & Gas Operator | Dec 2024 |
| 553 | Otter Exploration Inc | Warren, PA 16365-9689 | Oil & Gas Operator | Dec 2021 |
| 554 | Ows Acquisition Co LLC | Louisville, OH 44641 | Oil & Gas Operator | Dec 2024 |
| 555 | Ows Energy LLC | Carlton, PA 16311-1605 | Oil & Gas Operator | Sep 2025 |
| 556 | Oz Gas LTD | Tidioute, PA 16351-2648 | Oil & Gas Operator | Dec 2016 |
| 557 | P & C Energy Co | Allegany, NY 14706-9615 | Oil Operator | Dec 2015 |
| 558 | Pa DCNR State Parks Bur | Harrisburg, PA 17105-8551 | Gas Operator | Dec 2024 |
| 559 | Pa Dep Ofc Oil & Gas MGMT | Harrisburg, PA 17105-8765 | Gas Operator | Dec 1990 |
| 560 | Pa Gen Energy Co LLC | Warren, PA 16365-2510 | Oil & Gas Operator | Sep 2025 |
| 561 | Pa Gen Energy Corp | Warren, PA 16365-2510 | Oil & Gas Operator | Dec 2002 |
| 562 | Pa Land Holdings Corp | Waynesburg, PA 15370-3020 | Oil & Gas Operator | Dec 2011 |
| 563 | Pa Land Holdings LLC | Waynesburg, PA 15370-3020 | Gas Operator | Dec 2017 |
| 564 | Pa Mineral SVCS LLC | Indiana, PA 15701 | Oil & Gas Operator | Dec 2024 |
| 565 | Pa Prod SVC Inc | Indiana, PA 15701-0421 | Oil & Gas Operator | Dec 2024 |
| 566 | Pa State Sys Of Higher Ed Indiana Univ | Indiana, PA 15705-0001 | Gas Operator | Dec 2012 |
| 567 | Papesch Robert J | Waterford, PA 16441-4607 | Gas Operator | Dec 2024 |
| 568 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 569 | Patalon Robert E | Erie, PA 16505-0444 | Gas Operator | Dec 2024 |
| 570 | Patrick Shipley | Indiana, PA 15701-6501 | Oil & Gas Operator | Dec 2016 |
| 571 | Patriot Exploration Corp | Stahlstown, PA 15687-1301 | Oil & Gas Operator | Dec 2024 |
| 572 | PDC Mountaineer LLC | Bridgeport, WV 26330-9665 | Oil & Gas Operator | Dec 2017 |
| 573 | Peak Energy LLC | Coffeyville, KS 67337 | Oil & Gas Operator | Jun 2025 |
| 574 | Pecora Enterprises | Bradford, PA 16701-1026 | Oil & Gas Operator | Dec 1999 |
| 575 | Peggy J Bell | Sheffield, PA 16347-0776 | Oil & Gas Operator | Dec 2004 |
| 576 | Pembrooke Oil & Gas Inc | Franklin, PA 16323-7760 | Oil & Gas Operator | Dec 2024 |
| 577 | Pemco Gas Inc | Indian Harbor B, FL 32937 | Oil & Gas Operator | Dec 1997 |
| 578 | Penn VIew Exploration Inc | Blairsville, PA 15717-7961 | Oil & Gas Operator | Dec 2024 |
| 579 | Penn VIrginia Oil & Gas Corp | Houston, TX 77024 | Oil & Gas Operator | Dec 2023 |
| 580 | Penneco Oil Company, Inc. | Delmont, PA 15626-2408 | Oil & Gas Operator | Dec 2024 |
| 581 | Pennenergy Resources LLC | Pittsburgh, PA 15275-1063 | Oil & Gas Operator | Sep 2025 |
| 582 | Pennfield Energy LLC | Erie, PA 16510-4760 | Oil & Gas Operator | Dec 2021 |
| 583 | Pennhills Resources LLC | MT. Jewett, PA 16740 | Oil & Gas Operator | Sep 2025 |
| 584 | Pennzoil Prod Co | Vienna, WV 26105-2141 | Oil & Gas Operator | Dec 2000 |
| 585 | Pentex Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2003 |
| 586 | Peoples Gas Co LLC | Butler, PA 16001-4904 | Oil & Gas Operator | Dec 2005 |
| 587 | Peoples Natural Gas Co LLC | Pittsburgh, PA 15212 | Gas Operator | Dec 2016 |
| 588 | Petro Dev Corp | Bridgeport, WV 26330-0026 | Oil & Gas Operator | Dec 2013 |
| 589 | Petro Evaluation SVC Inc | Wooster, OH 44691-1223 | Oil & Gas Operator | Dec 2008 |
| 590 | Petro North LTD | Smethport, PA 16749-0742 | Oil & Gas Operator | Dec 2024 |
| 591 | Petro SVC Partners Inc | Indiana, PA 15701-8556 | Oil & Gas Operator | Dec 2024 |
| 592 | Petro Ventures Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2019 |
| 593 | Petrobank Opr Co | Denver, CO 80202-4675 | Gas Operator | Dec 1992 |
| 594 | Phillips Exploration Inc | Warrendale, PA 15086 | Oil & Gas Operator | Dec 2012 |
| 595 | Phillips Prod Co | Warrendale, PA 15086-7537 | Oil & Gas Operator | Dec 2011 |
| 596 | Phoenix Energy LLC | Warren, PA 16365-2302 | Oil & Gas Operator | Dec 2024 |
| 597 | Phoenix Energy Prod Inc | Freeport, PA 16229-1126 | Oil & Gas Operator | Dec 2024 |
| 598 | Pierce & Petersen | Warren, PA 16365 | Oil & Gas Operator | Dec 2024 |
| 599 | Pierce James E | Warren, PA 16365-0627 | Oil & Gas Operator | Dec 2011 |
| 600 | Pillar Energy Pa LLC | Charleston, WV 25312-5987 | Oil & Gas Operator | Dec 2024 |