| 501 | All In Energy Production Corp. | Red Rock, TX 78662 | Oil Operator | Dec 2025 |
| 502 | All Oil & Gas Inc. | | Oil & Gas Operator | Jul 1989 |
| 503 | All States Oil & Producing Co Inc | Canton, OH 44702 | Oil & Gas Operator | Dec 2018 |
| 504 | All-Southwest Petroleum, Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Oct 1997 |
| 505 | Allam Carl Oil C | | Oil Operator | Mar 1986 |
| 506 | Allam Kevin T Oi | | Oil Operator | Jun 1988 |
| 507 | Allam Production, Inc. | Hutchinson, KS 67504 | Oil & Gas Operator | Sep 2025 |
| 508 | Allam WM Robt Jr | | Oil Operator | Aug 1993 |
| 509 | Allar Co., The | Graham, TX 76450 | Oil & Gas Operator | Dec 2004 |
| 510 | Alleder Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 511 | Allegany Energy, Inc. | Belmont, NY 14813 | Oil & Gas Operator | Dec 2024 |
| 512 | Allegheny Enterprises Inc | Corsica, PA 15829-3833 | Oil & Gas Operator | Dec 2018 |
| 513 | Allegheny Natural Resources Inc | Gibsonia, PA 15044-8055 | Gas Operator | Dec 2019 |
| 514 | Allegheny Producers Inc | Cambridge, OH 43725 | Oil & Gas Operator | Dec 1984 |
| 515 | Allegiance Operating Inc. | Wichita Falls, TX 76307 | Oil Operator | Dec 2025 |
| 516 | Allegiant Resources, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Dec 2025 |
| 517 | Allegro Investments, Inc. | Victoria, TX 77903 | Oil & Gas Operator | Nov 2020 |
| 518 | Allegro Operating, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Dec 2025 |
| 519 | Allen & Allen Oil Co | | Oil Operator | Oct 2025 |
| 520 | Allen & Grace Oil Company | Kingsbury, TX 78638 | Oil & Gas Operator | Jul 1997 |
| 521 | Allen & Shumate, Inc. | Alice, TX 78333 | Oil & Gas Operator | Jan 1996 |
| 522 | Allen And Crouch | Casper, WY 82602 | Oil & Gas Operator | Mar 2020 |
| 523 | Allen And Schramm Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 1996 |
| 524 | Allen Benne | Ramona, OK 74061-3612 | Oil Operator | Aug 2010 |
| 525 | Allen Brothers | | Oil & Gas Operator | Dec 2024 |
| 526 | Allen Brothers Company | Oil City, LA 71061 | Oil & Gas Operator | Apr 1997 |
| 527 | Allen Delmar | Okemah, OK 74859-9801 | Oil & Gas Operator | Dec 2000 |
| 528 | Allen Drilling C | | Oil & Gas Operator | Nov 1994 |
| 529 | Allen Drilling Company | Great Bend, KS 67530 | Oil & Gas Operator | Dec 2009 |
| 530 | Allen Energy LLC | Cochranton, PA 16314-6214 | Oil & Gas Operator | Dec 2024 |
| 531 | Allen J D & Comp | | Oil Operator | Jan 1983 |
| 532 | Allen J W Revocable Trust | Tulsa, OK 74101-0411 | Oil Operator | Nov 1998 |
| 533 | Allen K Trobaugh | Midland, TX 79705 | Oil & Gas Operator | Mar 1997 |
| 534 | Allen Kent | Okemah, OK 74859-9700 | Oil Operator | Aug 2025 |
| 535 | Allen Mabel C | Dublin, OH 43017 | Oil Operator | Dec 1988 |
| 536 | Allen Michael | Broken Arrow, OK 74014-2239 | Oil & Gas Operator | Aug 2025 |
| 537 | Allen Oil & Gas LLC | Ardmore, OK 73401 | Oil Operator | Aug 2022 |
| 538 | Allen Oil Co. | Luling, TX 78648 | Oil & Gas Operator | Jun 2016 |
| 539 | Allen Operating Company, LLC | | Oil & Gas Operator | Dec 2022 |
| 540 | Allen Petroleum Company | | Oil Operator | Apr 1996 |
| 541 | Allen Petroleum, Inc. | | Oil Operator | Jul 2010 |
| 542 | Allen Richard R | Bartlesville, OK 74005 | Oil Operator | Aug 1999 |
| 543 | Allen Wade | Okmulgee, OK 74447-9717 | Oil & Gas Operator | Dec 2021 |
| 544 | Allen, C. L. (Doie) | Wichita Falls, TX 76309 | Oil & Gas Operator | Dec 2025 |
| 545 | Allen, Mabel F. | Corpus Chrsti, TX 78412 | Oil & Gas Operator | Jul 2002 |
| 546 | Allenco Energy Inc. | | Oil & Gas Operator | Oct 2025 |
| 547 | Allenergy Operating Co Inc | Coffeyville, KS 67337-6653 | Oil & Gas Operator | Mar 2015 |
| 548 | Allenergy, Inc. | Grove, OK 74345 | Oil & Gas Operator | Jul 2012 |
| 549 | Alliance Energy LLC | Hutchinson, KS 67501 | Oil & Gas Operator | Sep 2025 |
| 550 | Alliance Exploration Co., LLC | Tulsa, OK 74119 | Oil Operator | Apr 2017 |
| 551 | Alliance Exploration Corp. | | Oil & Gas Operator | Mar 1983 |
| 552 | Alliance Ogo, LP | Pleasanton, CA 94588 | Oil & Gas Operator | Dec 2025 |
| 553 | Alliance Oil & Gas Co Inc | Corinth, TX 76205 | Oil & Gas Operator | Mar 2015 |
| 554 | Alliance Operating Corporation | | Oil & Gas Operator | Jan 1995 |
| 555 | Alliance Petroleum Co., LLC | | Oil & Gas Operator | Dec 2021 |
| 556 | Alliance Petroleum Corporation | Canton, OH 44718-2553 | Oil & Gas Operator | Dec 2019 |
| 557 | Alliance Resources (USA), Inc. | | Oil & Gas Operator | Oct 2002 |
| 558 | Alliance Resources Corporation | Dallas, TX 75367 | Oil & Gas Operator | Nov 2024 |
| 559 | Alliance Resources LLC | Midland, TX 79705 | Oil & Gas Operator | Dec 2025 |
| 560 | Allie Oil | | Oil Operator | May 2000 |
| 561 | Allied Energy Corporation | | Oil & Gas Operator | Oct 2025 |
| 562 | Allied Energy Operating, LLC | McKinney, TX 75071 | Oil Operator | Dec 2025 |
| 563 | Allied Energy, Inc. | Saratoga, CA 95070 | Oil & Gas Operator | Dec 2021 |
| 564 | Allied Exploration, Inc. | | Oil & Gas Operator | May 2021 |
| 565 | Allied Oil Compa | | Oil & Gas Operator | Feb 1995 |
| 566 | Allied Oil Company, Inc. | Taneyville, MO 65759 | Oil Operator | Apr 1996 |
| 567 | Allied Oil Field Services LTD | Willoughby, OH 44094 | Oil & Gas Operator | Dec 2021 |
| 568 | Allied Operating LLC | Bowling Green, KY 42101-3980 | Oil & Gas Operator | Sep 2015 |
| 569 | Allied Operating Texas, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 570 | Allied Petroleum Company | | Gas Operator | Dec 1992 |
| 571 | Allied Petroleum Inc | Oklahoma City, OK 73116-1516 | Oil & Gas Operator | Jun 2014 |
| 572 | Allied Western Petroleum | | Oil & Gas Operator | Oct 2025 |
| 573 | Allied-Gulf Energy, LLC | Lafayette, LA 70508 | Oil & Gas Operator | Dec 2025 |
| 574 | Alligator Rock Well Service LLC | Velma, OK 73491-0627 | Oil & Gas Operator | Nov 2025 |
| 575 | Allison Bros DRLG Co Inc | | Oil & Gas Operator | Dec 2015 |
| 576 | Allison Dean Oil | | Oil & Gas Operator | Nov 1994 |
| 577 | Allison Energy Holdings LLC | Nichols Hills, OK 73116-5113 | Oil Operator | Oct 2025 |
| 578 | Allison J A | | Oil & Gas Operator | Nov 1995 |
| 579 | Allison Lease Services LLC | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 580 | Allison Oil Comp | | Oil Operator | Dec 1986 |
| 581 | Allison Operating Co., L.C. | Wichita, KS 67202 | Oil & Gas Operator | Dec 1998 |
| 582 | Allison Tom & Shelly Dba T & S Oil Company | Bartlesville, OK 74006-0722 | Oil & Gas Operator | May 2025 |
| 583 | Allison/Hobbs Inc. | Alba, TX 75410 | Oil & Gas Operator | Dec 2025 |
| 584 | Allshouse Terrence L Jr | Grand Valley, PA 16420-1930 | Oil & Gas Operator | Dec 2024 |
| 585 | Allsop Oil And Gas Company, Inc. | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Nov 1996 |
| 586 | Allstar Oil And Gas Inc. | | Oil & Gas Operator | Nov 1992 |
| 587 | Allstate Energy Corp | Smithville, WV 26178 | Oil & Gas Operator | Dec 2021 |
| 588 | Alltex Exploration, Inc. | Houston, TX 77056 | Oil & Gas Operator | Dec 2025 |
| 589 | Allwaste Oilfield Services Inc | | Oil Operator | May 1996 |
| 590 | Alma Gas Co Inc | Alma, NY 14708 | Gas Operator | Dec 2024 |
| 591 | Almac Engineering | Oklahoma City, OK 73116 | Oil & Gas Operator | Jan 2007 |
| 592 | Almack John And Glenda | Perry, OK 73077-8819 | Oil & Gas Operator | Apr 2016 |
| 593 | Alme, Henry A. | Cut Bank, MT 59427 | Gas Operator | Oct 2025 |
| 594 | Almond Crest Oil LLC | | Oil & Gas Operator | Oct 2025 |
| 595 | Almont Energy LLC | Kingfisher, OK 73750-0901 | Oil & Gas Operator | Oct 2021 |
| 596 | Aln Resources Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Jan 1993 |
| 597 | Alna Energy LLC | New Lexington, OH 43764 | Oil & Gas Operator | Dec 2023 |
| 598 | Alog, LLC | Brewton, AL 36427 | Oil & Gas Operator | Oct 2025 |
| 599 | Alpar Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Jul 2011 |
| 600 | Alpha Coal West Inc | Gillette, WY 82716 | Oil & Gas Operator | Jun 2020 |