| 501 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 502 | Sweetwater Exploration LLC | Norman, OK 73069-5636 | Oil & Gas Operator | Apr 2026 |
| 503 | SWN Production LLC | Spring, TX 77389-4954 | Oil & Gas Operator | Feb 2022 |
| 504 | T-K Exploration Company | Oklahoma City, OK 73102-7029 | Oil & Gas Operator | Mar 2015 |
| 505 | T2 Operating Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2026 |
| 506 | Tack Operating LLC | Oklahoma City, OK 73172-1492 | Oil & Gas Operator | Aug 2021 |
| 507 | Tahoe Exploration Inc. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2016 |
| 508 | Tapstone Energy LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | May 2026 |
| 509 | Tecolote Energy Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Jan 2024 |
| 510 | Temex Energy Inc | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 511 | Templar Operating LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Apr 2026 |
| 512 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Dec 2025 |
| 513 | Teocalli Exploration LLC | Kingfisher, OK 73750 | Oil & Gas Operator | May 2026 |
| 514 | Tepee Petroleum Company, Inc. | Houston, TX 77098 | Oil & Gas Operator | Feb 2014 |
| 515 | Tex/Con Oil & Gas Company | Houston, TX 77074 | Oil & Gas Operator | Feb 2001 |
| 516 | Texaco Exploration & Prod Inc | Houston, TX 77236 | Oil & Gas Operator | Mar 2026 |
| 517 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 518 | Texas Oil & Gas Corporation | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 519 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 520 | The William R Earnhardt Company | Bristow, OK 74010 | Oil & Gas Operator | Apr 2026 |
| 521 | Toklan Oil And Gas Corporation | Tulsa, OK 74136 | Oil & Gas Operator | May 2026 |
| 522 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 523 | Total Minatome Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 1998 |
| 524 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 525 | Trail Ridge Energy Partners, LLC | Grapevine, TX 76051 | Oil & Gas Operator | May 2026 |
| 526 | Transok LLC | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Jul 2020 |
| 527 | Trend Gas & Oil Inc | Jenks, OK 74037 | Oil & Gas Operator | Dec 2000 |
| 528 | Trenon Oil & Gas Inc | Oklahoma City, OK 73112-4279 | Oil & Gas Operator | Sep 1996 |
| 529 | Triad Energy, Inc. | Oklahoma City, OK 73105-1401 | Oil & Gas Operator | May 2026 |
| 530 | Trigg Drilling Company Inc | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2013 |
| 531 | Tripower Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2020 |
| 532 | Trout Disposal Well Inc | Hammon, OK 73650 | Oil & Gas Operator | Jan 2025 |
| 533 | Tulsa Energy Partners LLC | Tulsa, OK 74105 | Oil & Gas Operator | May 2026 |
| 534 | Turner Resources Inc | Hennessey, OK 73742 | Oil & Gas Operator | Apr 2026 |
| 535 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 536 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 537 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 538 | Unbridled Resources, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2026 |
| 539 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 540 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2026 |
| 541 | Upland Operating, LLC | Dallas, TX 75226 | Oil & Gas Operator | Jul 2026 |
| 542 | Upland Resources, Inc. | Canadian, TX 79014 | Oil & Gas Operator | Dec 2009 |
| 543 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Jul 2026 |
| 544 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Jul 2026 |
| 545 | Valpoint Operating, LLC | Amarillo, TX 79101 | Oil & Gas Operator | Jul 2026 |
| 546 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Mar 2026 |
| 547 | Viersen & Cochran Drilling Company | | Oil & Gas Operator | May 2015 |
| 548 | Vintage Petroleum, Inc. | Houston, TX 77046 | Oil & Gas Operator | Apr 2026 |
| 549 | Vitruvian II Woodford LLC | The Woodlands, TX 77381-5259 | Oil & Gas Operator | May 2019 |
| 550 | Wagner & Brown | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 551 | Wagner & Brown LP | Midland, TX 79702-1714 | Oil & Gas Operator | Aug 2022 |
| 552 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2026 |
| 553 | Wagon Wheel Production Company | Crawford, OK 73638-9502 | Oil & Gas Operator | Mar 2025 |
| 554 | Walsh Jr F Howard | Fort Worth, TX 76102-4773 | Oil & Gas Operator | Feb 2026 |
| 555 | Walsh Jr F Howard Opr Co Inc | Fort Worth, TX 76102-4773 | Oil & Gas Operator | Feb 2016 |
| 556 | Walters Oil Well Service Inc | Walters, OK 73572-0467 | Oil & Gas Operator | Nov 2000 |
| 557 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Apr 2026 |
| 558 | Warren American Oil Company LLC | Tulsa, OK 74147 | Oil & Gas Operator | Jul 2026 |
| 559 | Washita Oil And Gas, L.L.C. | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 560 | Weatherly Oil & Gas, LLC | Dallas, TX 75206 | Oil & Gas Operator | Jul 2026 |
| 561 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | May 2026 |
| 562 | Wheeler Richard Jr | Oklahoma City, OK 73112-8857 | Oil & Gas Operator | Mar 2005 |
| 563 | White Star Petroleum II LLC | Oklahoma City, OK 73113-1360 | Oil & Gas Operator | Apr 2026 |
| 564 | White Star Petroleum LLC | Oklahoma City, OK 73116-7906 | Oil & Gas Operator | Dec 2025 |
| 565 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jul 2026 |
| 566 | Whitmar Exploration Company | Denver, CO 80202 | Oil & Gas Operator | Apr 2026 |
| 567 | Whitmar Natural Resources Co | Tulsa, OK 74136-9998 | Oil & Gas Operator | Jun 2004 |
| 568 | Whitmar Operating Company | Tulsa, OK 74103-3515 | Oil & Gas Operator | Apr 2009 |
| 569 | Wildhorse Operating Company | Ardmore, OK 73402 | Oil & Gas Operator | Jul 2026 |
| 570 | Williford Energy Company | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2026 |
| 571 | Windsor Energy Group LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2021 |
| 572 | Wise James W | Okmulgee, OK 74447 | Oil & Gas Operator | Oct 1996 |
| 573 | WM KS Energy Resources LLC | Shreveport, LA 71101 | Oil & Gas Operator | Nov 2019 |
| 574 | WN Operating Inc | Okmulgee, OK 74447 | Oil & Gas Operator | Apr 2026 |
| 575 | Wolverine Exploration Company | Houston, TX 77002 | Oil & Gas Operator | May 2019 |
| 576 | Woods Petroleum Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 577 | WR Oil & Gas LLC | Plano, TX 75024-3523 | Oil & Gas Operator | Apr 2026 |
| 578 | Wroten Wiley Jr | Dallas, TX 75252 | Oil & Gas Operator | Jun 1994 |
| 579 | Xanadu Exploration Company | Broken Arrow, OK 74014 | Oil & Gas Operator | May 2026 |
| 580 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 581 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | May 2026 |
| 582 | Z G Exploration Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2005 |
| 583 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | May 2026 |
| 584 | Zephyr Operating Co LLC | Oklahoma City, OK 73118-6035 | Oil & Gas Operator | Apr 2026 |
| 585 | Zimtex Energy LLC | Perryton, TX 79070-5818 | Oil & Gas Operator | Nov 2017 |
| 586 | Zinke & Trumbo LTD | Tulsa, OK 74105 | Oil & Gas Operator | Sep 2017 |