| 501 | Lester L Moyer | Cooperstown, PA 16317-2917 | Gas Operator | Dec 2009 |
| 502 | Lightning Oil Co LTD | Mentor, OH 44060-4963 | Gas Operator | Dec 1998 |
| 503 | Lincoln MGMT Co | Greensburg, PA 15601-5200 | Oil & Gas Operator | Dec 2017 |
| 504 | Lindell & Maney | Warren, PA 16365-3643 | Oil & Gas Operator | Dec 2008 |
| 505 | Lindell & Maney LLC | Warren, PA 16365-3670 | Oil & Gas Operator | Dec 2025 |
| 506 | Linn Opr Inc | Indiana, PA 15701-8914 | Oil & Gas Operator | Dec 2007 |
| 507 | Linn Opr LLC | Indiana, PA 15701-8914 | Gas Operator | Dec 2004 |
| 508 | Lion Energy Co LLC | Wexford, PA 15090-6315 | Oil & Gas Operator | Dec 2014 |
| 509 | Loan Asset Issuer LLC, Series 2021 NG-1 | New York, NY 10022 | Oil & Gas Operator | Dec 2025 |
| 510 | Locin Oil Corporation | Katy, TX 77494 | Oil & Gas Operator | Feb 2026 |
| 511 | Lola Energy Petroco LLC | Canonsburg, PA 15317 | Gas Operator | Dec 2025 |
| 512 | Lord Corp | Erie, PA 16505-5120 | Gas Operator | Dec 1994 |
| 513 | Louden Clarence E Jr | Kittanning, PA 16201-1121 | Gas Operator | Dec 1994 |
| 514 | LPR Energy, LLC | Dallas, TX 75219 | Oil & Gas Operator | Feb 2026 |
| 515 | LT Oil Co LLC | Pleasantville, PA 16341-0144 | Oil Operator | Dec 2025 |
| 516 | Lulu & Thomas Kavouras | Apollo, PA 15613-1108 | Oil & Gas Operator | Dec 2023 |
| 517 | M & M Royalty LTD | North Canton, OH 44720 | Oil & Gas Operator | Dec 2016 |
| 518 | M4 Energy, LLC | Watsontown, PA 17777-1133 | Oil & Gas Operator | Dec 2025 |
| 519 | Mac Mar Inc | Blairsville, PA 15717-7646 | Oil & Gas Operator | Dec 2025 |
| 520 | Madison Mark T | Marienville, PA 16239-6029 | Oil & Gas Operator | Dec 2012 |
| 521 | Madtick Dev Corp | Punxsutawney, PA 15767-0140 | Oil & Gas Operator | Dec 2024 |
| 522 | Maney McNeal Oil & Gas | | Oil & Gas Operator | Dec 1999 |
| 523 | Manufacturers Light & Heat Co | Pittsburgh, PA 15219 | Gas Operator | Dec 1986 |
| 524 | Manx Inc | Pleasantville, PA 16341-1229 | Oil Operator | Dec 2020 |
| 525 | Maple Grove Enterprises Inc | Rimersburg, PA 16248-6415 | Oil & Gas Operator | Dec 2025 |
| 526 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Dec 2025 |
| 527 | Marco Drilling Inc | Monroeville, PA 15146-0278 | Oil & Gas Operator | Dec 2024 |
| 528 | Margaret Merganser Inc | Tionesta, PA 16353-5853 | Oil & Gas Operator | Dec 2008 |
| 529 | Mark & Troy Johnson | Sugar Grove, PA 16350-5938 | Oil Operator | Dec 2025 |
| 530 | Mark A & Michael J Midlik | Warren, PA 16365-2029 | Oil & Gas Operator | Dec 2015 |
| 531 | Mark Resources Corp | Pittsburgh, PA 15276 | Oil & Gas Operator | Dec 1993 |
| 532 | Marvin Sanders Oil | Sugar Grove, PA 16350-5612 | Oil & Gas Operator | Dec 2016 |
| 533 | Mat Oil & Gas Exploration Inc | Indiana, PA 15701-8931 | Gas Operator | Dec 1993 |
| 534 | Maxson Gas Corp | Shinglehouse, PA 16748-0436 | Oil & Gas Operator | Dec 2024 |
| 535 | Maxson Lawrence C | Shinglehouse, PA 16748 | Oil & Gas Operator | Dec 2016 |
| 536 | Maxwell Bros | Clarion, PA 16214-7446 | Oil & Gas Operator | Dec 2025 |
| 537 | Mays Coal Co | Clarion, PA 16214-0447 | Gas Operator | Dec 2003 |
| 538 | Mays Gas & Coal Co | Clarion, PA 16214-0447 | Oil & Gas Operator | Dec 2025 |
| 539 | MBS Resources Inc | Wilcox, PA 15870-1810 | Oil & Gas Operator | Dec 2025 |
| 540 | MC123 LLC | Indiana, PA 15701-8718 | Gas Operator | Dec 2025 |
| 541 | McCabe & Co | Albion, PA 16401-8013 | Oil & Gas Operator | Dec 1994 |
| 542 | McCall Carl E | Fairmount City, PA 16224 | Oil & Gas Operator | Dec 2025 |
| 543 | McCluskey J Sterling | New York, NY 10128-1008 | Gas Operator | Dec 1989 |
| 544 | McComb Oil Inc | Stoneboro, PA 16153-3017 | Oil & Gas Operator | Dec 2025 |
| 545 | McCool John E | Youngsville, PA 16371 | Oil & Gas Operator | Dec 2025 |
| 546 | McCoy Natural Gas Co | Oil City, PA 16301-3003 | Gas Operator | Dec 1995 |
| 547 | McKenna Oil Co | Kane, PA 16735-9711 | Oil & Gas Operator | Dec 2004 |
| 548 | MCQ Natural Gas Co Inc | Leechburg, PA 15656-0594 | Gas Operator | Dec 2012 |
| 549 | MDS Energy Dev LLC | Kittanning, PA 16201-4403 | Oil & Gas Operator | Dec 2025 |
| 550 | MDS Energy LTD | Kittanning, PA 16201-4403 | Gas Operator | Feb 2015 |
| 551 | Mead Oil LLC | Sheffield, PA 16347-1022 | Oil & Gas Operator | Dec 2025 |
| 552 | Meadville Forging Co LP | Meadville, PA 16335-0459 | Gas Operator | Dec 1997 |
| 553 | Medina Res Dev Co LLC | Cambridge Springs, PA 16403-3447 | Oil & Gas Operator | Dec 2025 |
| 554 | Meridian Exploration Corp. | Pittsburgh, PA 15222 | Oil & Gas Operator | Dec 2021 |
| 555 | Meridian Oil & Gas Enterprises Inc | Blairsville, PA 15717-0337 | Oil & Gas Operator | Dec 2003 |
| 556 | Mervin Troyer | Union City, PA 16438-8510 | Gas Operator | Dec 2008 |
| 557 | Mid Amer Natural Resources Inc | Erie, PA 16505-4760 | Gas Operator | Dec 1994 |
| 558 | Mid East Oil Co | Indiana, PA 15701-5378 | Gas Operator | Dec 2006 |
| 559 | Mid-Penn Energy Corporation | Harrisburg, PA 17101-1002 | Gas Operator | Dec 2021 |
| 560 | Mieka LLC | Flower Mound, TX 75028-7446 | Oil & Gas Operator | Dec 2014 |
| 561 | Millennium Oil & Gas Inc | Dexter, KS 67038 | Oil & Gas Operator | Dec 2024 |
| 562 | Minard Run Oil Co | Bradford, PA 16701 | Oil & Gas Operator | Dec 2025 |
| 563 | Minteer & Baker Gas Enterprise | Kittanning, PA 16201-5022 | Gas Operator | Dec 2025 |
| 564 | Minter Lee M | Bradford, PA 16701-3763 | Gas Operator | Dec 1991 |
| 565 | Missing Moon Oil Inc | Knox, PA 16232-4507 | Oil & Gas Operator | Dec 2024 |
| 566 | Mitch Well Energy Inc | Waterford, PA 16441-8143 | Oil & Gas Operator | Dec 2012 |
| 567 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 568 | Mob Corp | Waynesburg, PA 15370-2036 | Gas Operator | Dec 2007 |
| 569 | Mohr Hans | Carmichaels, PA 15320-2627 | Gas Operator | Dec 2014 |
| 570 | Monona LLC | Ligonier, PA 15658-0612 | Gas Operator | Dec 2025 |
| 571 | Monroe Res LTD | Fairport, NY 14450-3218 | Gas Operator | Dec 2004 |
| 572 | Mount Chestnut Dev LLC | Butler, PA 16002-3940 | Gas Operator | Dec 2017 |
| 573 | MSL Oil & Gas Corp | Bradford, PA 16701-0151 | Oil & Gas Operator | Dec 2025 |
| 574 | MT Savage Refractories | Pittsburgh, PA 15206-0171 | Gas Operator | Dec 2021 |
| 575 | MTN Energy | Aleppo, PA 15310 | Oil & Gas Operator | Dec 2025 |
| 576 | MTN V Oil & Gas Inc | Indiana, PA 15701-8914 | Oil & Gas Operator | Dec 2025 |
| 577 | Murphy Prod Inc | Vanderbilt, PA 15486-1001 | Oil & Gas Operator | Dec 2025 |
| 578 | Mutig Energies Inc | Sarver, PA 15055 | Oil & Gas Operator | Dec 2023 |
| 579 | Mutual Oil & Gas Co | Akron, OH 44311 | Oil & Gas Operator | Dec 2000 |
| 580 | Natl Fuel Gas Supply Corp | Williamsville, NY 14221-5887 | Oil & Gas Operator | Dec 2009 |
| 581 | Natural Energy Dev Corp | Pittsburgh, PA 15241-1548 | Oil & Gas Operator | Dec 2018 |
| 582 | Natural Oil & Gas Corp | Bradford, PA 16701 | Oil & Gas Operator | Dec 2023 |
| 583 | NCL Natural Resources LLC | Spring, TX 77381-5261 | Oil & Gas Operator | Dec 2017 |
| 584 | Nea Cross Inc | Erie, PA 16508-2769 | Gas Operator | Dec 1991 |
| 585 | New Century Energy Inc | MC Donald, PA 15057-2163 | Oil & Gas Operator | Dec 2021 |
| 586 | New York Natural Gas Corp | Pittsburgh, PA 15222-1402 | Gas Operator | Dec 1990 |
| 587 | Niche Energy LLC | Waterford, PA 16441-9125 | Gas Operator | Dec 2025 |
| 588 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 589 | Norbert J Baumgart | Warren, PA 16365-3403 | Oil & Gas Operator | Dec 2009 |
| 590 | Nornew Inc | Houston, TX 77063-2140 | Oil & Gas Operator | Dec 2008 |
| 591 | North Amer Oil & Gas Drilling Co Inc | Pleasantville, PA 16341-0197 | Oil Operator | Dec 1999 |
| 592 | North Cambria Fuel Co | Blairsville, PA 15717-7961 | Gas Operator | Dec 2008 |
| 593 | North East Gas & Oil Co | Scottsville, VA 24590-3962 | Oil & Gas Operator | Dec 2013 |
| 594 | North Fork Oil & Gas Inc | Brookville, PA 15825-7976 | Gas Operator | Dec 2005 |
| 595 | North John M | Valatie, NY 12184-5005 | Gas Operator | Dec 2014 |
| 596 | North Penn Gas Co | Allentown, PA 18101-1139 | Gas Operator | Dec 2000 |
| 597 | North Star Energy Resources LLC | Waynesburg, PA 15370-3833 | Gas Operator | Dec 2024 |
| 598 | Northeast Natural Energy LLC | Charleston, WV 25301-2719 | Oil & Gas Operator | Dec 2025 |
| 599 | Northeastern Exploration Corp | Gibsonia, PA 15044-9208 | Gas Operator | Dec 1998 |
| 600 | Northeastern Opr Co Inc | Shelocta, PA 15774-2346 | Gas Operator | Dec 2025 |