| 501 | Aggie Oil Company | Lakewood, CO 80226 | Oil & Gas Operator | May 2001 |
| 502 | Aggietech Oil, LTD. | Midland, TX 79701 | Oil & Gas Operator | Aug 2016 |
| 503 | Aghorn Operating, Inc. | Odessa, TX 79768 | Oil & Gas Operator | May 2026 |
| 504 | Agip Petroleum Co., Inc. | | Oil & Gas Operator | Jan 2003 |
| 505 | Agis Energy Inc. | Lafayette, LA 70508 | Oil & Gas Operator | May 2026 |
| 506 | Agis Energy LLC | Lafayette, LA 70508 | Oil & Gas Operator | May 2026 |
| 507 | Agp Energy Services LLC | Midland, TX 79701 | Oil & Gas Operator | May 2026 |
| 508 | Agri-Acres Inc | Billings, MT 59103 | Oil Operator | Jun 1996 |
| 509 | Agricultural Energy Services | Edmond, OK 73003 | Oil & Gas Operator | Jan 2026 |
| 510 | Agricultural Energy Services Inc | Edmond, OK 73012 | Oil Operator | Mar 2026 |
| 511 | Agroil, Inc. | Brownwood, TX 76801 | Oil & Gas Operator | May 2026 |
| 512 | Agua Sucia LLC | Lovington, NM 88260 | Oil & Gas Operator | Jul 2018 |
| 513 | Aguila Operating Company LLC | Edmond, OK 73034 | Oil & Gas Operator | Mar 2026 |
| 514 | Agv Corp. | Attica, KS 67009 | Oil & Gas Operator | Jan 2026 |
| 515 | Ah Operating, LLC | Midland, TX 79710 | Gas Operator | May 2026 |
| 516 | Ahabb Oil | Luling, TX 78648 | Oil & Gas Operator | Dec 1998 |
| 517 | Aicr LLC | Odessa, TX 79768 | Oil Operator | May 2026 |
| 518 | Aiello Bros Oil & Gas Inc | Bradford, PA 16701-2925 | Oil & Gas Operator | Dec 2025 |
| 519 | Aikins Drilling Company | Mohave Valley, AZ 86440 | Oil Operator | Dec 2019 |
| 520 | Aikman Brothers, LLC | Amarillo, TX 79109 | Oil & Gas Operator | Feb 2026 |
| 521 | Aikman Oil Corp. | Oklahoma City, OK 73157 | Oil & Gas Operator | May 2026 |
| 522 | Ailey A C | Stroud, OK 74079-9209 | Oil & Gas Operator | Nov 2021 |
| 523 | Aim Consultants Inc. | Rockville, MD 20852 | Oil & Gas Operator | Mar 2008 |
| 524 | Aim Energy LLC | North Canton, OH 44720 | Oil & Gas Operator | Dec 2025 |
| 525 | Ainsworth Operat | | Oil Operator | Apr 1995 |
| 526 | Ainsworth Operating Co. | Salem, OR 97302 | Oil Operator | Jan 2026 |
| 527 | Ainsworth Prod Co. | | Oil Operator | Aug 1986 |
| 528 | Ainsworth Rig Service, LLC | | Oil Operator | Nov 2024 |
| 529 | Ainsworth, Otis | | Oil & Gas Operator | Jun 1987 |
| 530 | Airdale Oil & Gas LLC | Oil City, PA 16301-3771 | Oil & Gas Operator | Dec 2025 |
| 531 | Aix Energy Inc | | Oil & Gas Operator | Jul 2016 |
| 532 | Aix Energy LLC | | Oil & Gas Operator | Feb 2026 |
| 533 | Aj Oil, Inc. | Springfield, LA 70462 | Oil Operator | Oct 2019 |
| 534 | Aj'S Pump Truck Service, Inc. | Odessa, TX 79760 | Oil & Gas Operator | May 2026 |
| 535 | Ajar International, Inc. | Randolph, NY 14772 | Gas Operator | Dec 2024 |
| 536 | Ajax Oil & Gas C | | Oil & Gas Operator | Jun 1989 |
| 537 | Ajax Oil Company | Billings, MT 59103 | Oil & Gas Operator | Dec 2003 |
| 538 | Ajax Resources, LLC | Houston, TX 77046 | Oil & Gas Operator | May 2026 |
| 539 | Ajb Oil LLC | Tulsa, OK 74114-5218 | Oil Operator | Jan 2026 |
| 540 | Ak Operating Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2026 |
| 541 | Ak Pearson Family Trust | Amarillo, TX 79114 | Oil Operator | May 2026 |
| 542 | Akandas, Inc. | Chanute, KS 66720 | Oil Operator | Aug 2002 |
| 543 | Akea, Inc. | Holliday, TX 76366 | Oil Operator | May 2026 |
| 544 | Aker Oil & Gas Company | Tulsa, OK 74105-2216 | Oil & Gas Operator | Aug 2013 |
| 545 | Akers & Fultz, Inc. | Graham, TX 76450 | Oil & Gas Operator | Jun 2003 |
| 546 | Akers, B. F. | Graham, TX 76450 | Oil & Gas Operator | May 2026 |
| 547 | Akers, Bill | Hebbronville, TX 78361 | Oil & Gas Operator | Aug 2003 |
| 548 | Akg Operating Company | Austin, TX 78701 | Oil & Gas Operator | May 2026 |
| 549 | Akin Beene Resources LLC | | Oil & Gas Operator | May 2016 |
| 550 | Akin Jr Verna M & Emsley F | Maud, OK 74854 | Oil & Gas Operator | Apr 2002 |
| 551 | Akins Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2026 |
| 552 | Akma, Inc. | Ore City, TX 75683 | Oil & Gas Operator | Apr 1999 |
| 553 | Akron Central School District | Akron, NY 14001 | Gas Operator | Dec 2024 |
| 554 | Akron Oil Corp | Hackensack, NJ 07602 | Oil & Gas Operator | Dec 1989 |
| 555 | Aksarben Petroleum, Inc. | | Oil Operator | Sep 2022 |
| 556 | Al & D.L. Chiles | | Oil & Gas Operator | Jul 1991 |
| 557 | Al Chiles II | | Oil Operator | Jan 2025 |
| 558 | Al Merit Energy Co., Inc. | | Oil & Gas Operator | Jun 2015 |
| 559 | Al-La-Lyn Oil, Inc. | Ellis, KS 67637 | Oil Operator | Nov 2003 |
| 560 | Alacia Operating Company | Freer, TX 78357 | Oil & Gas Operator | May 2026 |
| 561 | Aladdin Energy, Inc. | Richardson, TX 75080 | Oil & Gas Operator | Feb 1999 |
| 562 | Aladdin Petroleu | | Oil & Gas Operator | Nov 1995 |
| 563 | Aladdin Petroleum Corporation | Wichita, KS 67202 | Oil & Gas Operator | Jan 2021 |
| 564 | Alagood & Alagood | | Oil & Gas Operator | May 1981 |
| 565 | Alameda Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 1994 |
| 566 | Alameda Oil Company | | Oil Operator | Mar 1998 |
| 567 | Alamo Operating Company, L. C. | San Antonio, TX 78278 | Oil & Gas Operator | Aug 2023 |
| 568 | Alamo Permian Resources, LLC | Midland, TX 79701 | Oil & Gas Operator | Oct 2016 |
| 569 | Alamo Petroleum Company | | Oil & Gas Operator | Jun 1985 |
| 570 | Alamo Resources Inc | Dallas, TX 75229 | Oil & Gas Operator | Dec 2000 |
| 571 | Alamosa Drilling Inc | Dallas, TX 75206-1841 | Oil & Gas Operator | Apr 2024 |
| 572 | Alamosa Operating Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 2026 |
| 573 | Alan Howard Karchmer Living Trust | | Oil Operator | Dec 2022 |
| 574 | Alanmar Energy | | Gas Operator | Jan 2018 |
| 575 | Alaron Energy, Inc. | Irving, TX 75038 | Oil & Gas Operator | May 2026 |
| 576 | Alaska Development Company | | Oil Operator | Dec 1933 |
| 577 | Alb, Inc. | Great Bend, KS 67530 | Oil Operator | Dec 2025 |
| 578 | Albany Well Service | Albany, TX 76430 | Oil & Gas Operator | May 2026 |
| 579 | Albemarle Corporation | Magnolia, AR 71753 | Oil & Gas Operator | Jan 2025 |
| 580 | Albert E. Smith Oil | | Oil Operator | Feb 2026 |
| 581 | Albert R. Braun Oil Operations, LLC (Estate) | Hays, KS 67601 | Oil Operator | Jan 2026 |
| 582 | Albert Thornbrough Trust | Boca Raton, FL 33432 | Gas Operator | Jan 2026 |
| 583 | Albert, David Oil & Gas | Dallas, TX 75240 | Oil & Gas Operator | Mar 2008 |
| 584 | Albert-Bishop Exploration Co Inc | Dallas, TX 75240 | Oil & Gas Operator | Feb 2007 |
| 585 | Alberta Gas Company | Vernal, UT 84078 | Oil & Gas Operator | Nov 2021 |
| 586 | Albrecht, Phil A., Jr. | Victoria, TX 77901 | Oil & Gas Operator | Jun 2005 |
| 587 | Albright Paul D Or Inger J | Okemah, OK 74859-9309 | Oil & Gas Operator | Feb 2026 |
| 588 | Albritton Resources Inc | Dallas, TX 75206 | Oil & Gas Operator | Feb 2001 |
| 589 | Alchemist Energy, LLC | Irving, TX 75062 | Oil & Gas Operator | May 2026 |
| 590 | Alchemy Farms LLC | Hamburg, NY 14075 | Gas Operator | Dec 2024 |
| 591 | Alco DRLG. Co. | Freer, TX 78357 | Oil & Gas Operator | May 2026 |
| 592 | Alco Ind | Valley Forge, PA 19482-0937 | Gas Operator | Dec 2024 |
| 593 | Alco Oil & Gas | Lafayette, LA 70130 | Oil & Gas Operator | Dec 1970 |
| 594 | Alco Oil & Gas Co. LLC | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2026 |
| 595 | Alcon H2oil LLC | Pecos, TX 79772 | Oil & Gas Operator | Jan 2026 |
| 596 | Alcor Energy, Inc. | San Antonio, TX 78239 | Oil & Gas Operator | May 2026 |
| 597 | Alcorn Energy, L.L.C. | Woodway, TX 76712 | Oil Operator | May 2026 |
| 598 | Alcorn Prod Co. | Victoria, TX 77902 | Oil & Gas Operator | Mar 1997 |
| 599 | Alcorn, Jerry D. | Grand Prairie, TX 75050 | Oil & Gas Operator | May 2026 |
| 600 | Alcove Investments | Apollo, PA 15613-9720 | Oil & Gas Operator | Dec 2025 |