| 401 | Anatexas Offshore, Inc. | Houston, TX 77024 | Oil & Gas Operator | Apr 2024 |
| 402 | Anathema, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Dec 1994 |
| 403 | Ancell Oil Co. | Wichita Falls, TX 76309 | Oil & Gas Operator | Dec 2018 |
| 404 | Anchor B Production, Inc. | Orla, TX 79770 | Oil & Gas Operator | Aug 2003 |
| 405 | Anchor Oil Company | Gruver, TX 79040 | Gas Operator | Apr 2024 |
| 406 | Anchor Operating Co. | Houston, TX 77055 | Oil & Gas Operator | Apr 2024 |
| 407 | Anco Account | Wichita Falls, TX 76301 | Oil & Gas Operator | Oct 1995 |
| 408 | Andalucia Oil Company | San Antonio, TX 78258 | Oil Operator | Apr 2024 |
| 409 | Andector Exploration Company | Midland, TX 79702 | Oil & Gas Operator | Apr 2024 |
| 410 | Anderman/Smith Operating Company | Tulsa, OK 74136 | Oil & Gas Operator | Sep 1995 |
| 411 | Anderson Energy Corporation | Arvada, CO 80004 | Oil & Gas Operator | Apr 2024 |
| 412 | Anderson Oil & Gas Account | Wichita Falls, TX 76301 | Oil & Gas Operator | Nov 2013 |
| 413 | Anderson Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Dec 2015 |
| 414 | Anderson Oil Corporation | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Nov 1999 |
| 415 | Anderson Oil LTD. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2024 |
| 416 | Anderson Petro-Equipment, Inc. | Montgomery, TX 77356 | Oil & Gas Operator | Apr 2024 |
| 417 | Anderson Producing, Inc. | Houston, TX 77057 | Oil & Gas Operator | Sep 2013 |
| 418 | Anderson Production | Cisco, TX 76437 | Oil & Gas Operator | Apr 2024 |
| 419 | Anderson, Carl T. | Wichita Falls, TX 76301 | Oil & Gas Operator | Feb 2014 |
| 420 | Anderson, Dorman | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2012 |
| 421 | Anderson, E D | Cisco, TX 76437 | Oil & Gas Operator | Nov 2009 |
| 422 | Anderson, James K. Inc. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2024 |
| 423 | Anderson, Roger W. Corp. | Clyde, TX 79510 | Oil & Gas Operator | Apr 2020 |
| 424 | Anderson, Steven C. | Victoria, TX 77902 | Gas Operator | Jun 2004 |
| 425 | Ando Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 1998 |
| 426 | Andrew Alan Exploration, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2017 |
| 427 | Andrew, Robert Oneal | Olney, TX 76374 | Oil & Gas Operator | Sep 1998 |
| 428 | Andrews & Corkran, L.L.C. | Austin, TX 78746 | Oil & Gas Operator | Feb 2000 |
| 429 | Andrews, B. C. | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 430 | Andrus Resources Corporation | Houston, TX 77046 | Oil & Gas Operator | Oct 2002 |
| 431 | Anegada Resources | Kerrville, TX 78029 | Oil & Gas Operator | Jan 2002 |
| 432 | Anejo Production, LLC | Electra, TX 76360 | Oil & Gas Operator | Apr 2024 |
| 433 | Angel Operating LLC | Metairie, LA 70033 | Oil Operator | Apr 2024 |
| 434 | Angelo, Ernest, Jr. | Midland, TX 79701 | Oil & Gas Operator | Mar 2008 |
| 435 | Angle Oil Company | Hays, KS 67601 | Oil Operator | Sep 2002 |
| 436 | Animas Minerals LLC | Corpus Chrsti, TX 78413 | Oil Operator | Apr 2024 |
| 437 | Anloc, LLC | Houston, TX 77024 | Oil & Gas Operator | Apr 2019 |
| 438 | Anr Production Company | Houston, TX 77046 | Oil & Gas Operator | Aug 2017 |
| 439 | Anschutz Exploration Corporation | Denver, CO 80202 | Oil & Gas Operator | Apr 2024 |
| 440 | Anson Company | Oklahoma City, OK 73124 | Oil & Gas Operator | Apr 2018 |
| 441 | Antara Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Apr 2004 |
| 442 | Antares Energy Company | Houston, TX 77010 | Oil & Gas Operator | Apr 2024 |
| 443 | Antares Oil Corp | Denver, CO 80202 | Oil & Gas Operator | Oct 2015 |
| 444 | Antelope Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2024 |
| 445 | Antelope Energy Partners, LLC | Houston, TX 77043 | Oil & Gas Operator | Apr 2024 |
| 446 | Antelope Production Co. | Midland, TX 79701 | Oil & Gas Operator | Oct 1995 |
| 447 | Antelope Resources Inc | Billings, MT 59101 | Oil & Gas Operator | May 2017 |
| 448 | Antero Resources I, LP | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 449 | Antero Resources II, LP | Denver, CO 80202 | Oil & Gas Operator | May 2006 |
| 450 | Anthony Oil & Gas Co. | Shreveport, LA 71135 | Oil Operator | May 1993 |
| 451 | Anthony, Bob G. Inc. | Brookhaven, MS 39601 | Oil & Gas Operator | Apr 2024 |
| 452 | Antilley, Joe | Abilene, TX 79602 | Oil & Gas Operator | Jan 2024 |
| 453 | Antle Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 454 | Antle, E. | Graham, TX 76450 | Oil & Gas Operator | Oct 1994 |
| 455 | Aoco Operating Company, L.L.C. | Houston, TX 77008 | Oil & Gas Operator | Feb 2005 |
| 456 | Aoco Operating, L.P. | Houston, TX 77008 | Oil & Gas Operator | Mar 2008 |
| 457 | Aog, Inc. | Norman, OK 73070 | Oil & Gas Operator | Nov 2014 |
| 458 | Aop Operating Corporation | Dallas, TX 75313 | Oil & Gas Operator | Aug 2003 |
| 459 | Ap Operating, Inc. | Plano, TX 75074 | Oil & Gas Operator | Apr 2024 |
| 460 | Apache Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2024 |
| 461 | Apache Energy Resources Corp | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 462 | Apache Oil Company | San Antonio, TX 78227 | Oil & Gas Operator | Apr 2024 |
| 463 | Apache Production Company | Holliday, TX 76366 | Oil & Gas Operator | Apr 2024 |
| 464 | Apache Shelf, Inc. | Houston, TX 77056 | Oil & Gas Operator | Jan 2014 |
| 465 | Apb Oil Corporation | Houston, TX 77052 | Oil & Gas Operator | Apr 1996 |
| 466 | Apc Operating Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Oct 1996 |
| 467 | Apex Energy, Inc. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Apr 2024 |
| 468 | Apex Oil & Gas, Inc. | Houston, TX 77067 | Oil & Gas Operator | Oct 2009 |
| 469 | Apex Operating & Equip. Co. | Bowie, TX 76230 | Oil & Gas Operator | Nov 2003 |
| 470 | Apex Production LTD. | Albany, TX 76430 | Oil Operator | Apr 2024 |
| 471 | Apex Resources Inc | Allison Park, PA 15101-3838 | Oil & Gas Operator | Dec 1993 |
| 472 | Apex Royalties, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 1997 |
| 473 | Apexco, Inc. | Sand Springs, OK 74063 | Oil & Gas Operator | Dec 2023 |
| 474 | API Operating Co. | Houston, TX 77036 | Oil & Gas Operator | Apr 2024 |
| 475 | Apollo Energy Operating Co, LP | Lake Charles, LA 70601 | Oil & Gas Operator | Dec 2023 |
| 476 | Appling, J. B. | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 477 | Approach Operating LLC | Fort Worth, TX 76116 | Oil & Gas Operator | Sep 2020 |
| 478 | Apr Operating LLC | Midland, TX 79701 | Oil & Gas Operator | Apr 2024 |
| 479 | Apv McCamey LLC | MC Camey, TX 79752 | Oil & Gas Operator | Apr 2024 |
| 480 | Apx & Assoc. | FT Stockton, TX 79735 | Oil & Gas Operator | Sep 1998 |
| 481 | Aquila Energy Resources Corp. | Houston, TX 77042 | Oil & Gas Operator | Nov 2013 |
| 482 | Aquinas Oil & Gas, LLC | Muenster, TX 76252 | Oil Operator | Apr 2024 |
| 483 | Arabella Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2024 |
| 484 | Arabella Petroleum Company, LLC | Austin, TX 78701 | Oil & Gas Operator | Apr 2024 |
| 485 | Arabie, Inc. | Lake Charles, LA 70605 | Oil & Gas Operator | Apr 2024 |
| 486 | Araluen Energy, Inc. | Houston, TX 77094 | Oil Operator | Jun 2022 |
| 487 | Aramco Petroleum LLC | Burkburnett, TX 76354 | Oil Operator | Apr 2024 |
| 488 | Aransas DRLG & Workover Co Inc | Corpus Chrsti, TX 78409 | Oil & Gas Operator | Jul 2019 |
| 489 | Aransas Oil Company, Inc. | San Antonio, TX 78253 | Oil & Gas Operator | Jan 1999 |
| 490 | Aransas Resources, Inc | Houston, TX 77083 | Oil & Gas Operator | Dec 2005 |
| 491 | Aransas Resources, LP | Houston, TX 77006 | Oil & Gas Operator | Oct 2006 |
| 492 | Arapahoe Prod. Co. | Borger, TX 79008 | Oil & Gas Operator | May 2012 |
| 493 | Arapahoe Resources LLC | Oklahoma City, OK 73157-7107 | Oil & Gas Operator | Dec 2023 |
| 494 | Aratex Production Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2003 |
| 495 | Araxas Exploration, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Apr 1998 |
| 496 | Arbco, Inc. | Lafayette, LA 70505 | Oil & Gas Operator | Jan 1996 |
| 497 | Arben Oil, Inc. | Coleman, TX 76834 | Oil & Gas Operator | Apr 2024 |
| 498 | Arbol Resources, Inc. | Houston, TX 77079 | Oil & Gas Operator | Apr 2024 |
| 499 | Arc Energy Inc. | Dallas, TX 75227 | Oil Operator | Apr 2024 |
| 500 | Arcadia Expl. & Prod. Company | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2011 |