| 601 | Tri-Tex Exploration LTD | Abilene, TX 79608 | Oil Operator | Apr 2019 |
| 602 | Triangle P Development Corp. | Bronte, TX 76933 | Oil & Gas Operator | Feb 2026 |
| 603 | Triforce Energy LLC | Littleton, CO 80122 | Oil & Gas Operator | Feb 2026 |
| 604 | Trinity Minerals&Operating Corp. | Abilene, TX 79605 | Oil & Gas Operator | Dec 1995 |
| 605 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 606 | Trumter Petroleum Corporation | Fort Worth, TX 76185 | Oil & Gas Operator | Aug 1998 |
| 607 | TSW Oil & Gas, LLC | Abilene, TX 79602 | Oil & Gas Operator | Jan 2016 |
| 608 | Tucker Drilling Company, Inc. | San Angelo, TX 76903 | Oil & Gas Operator | Jul 1996 |
| 609 | Tuthill & Barbee | Amarillo, TX 79101 | Oil & Gas Operator | Nov 1994 |
| 610 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 611 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | Feb 2026 |
| 612 | United Operating Company | Olney, TX 76374 | Oil & Gas Operator | Aug 2003 |
| 613 | Upland Resources LLC | Canadian, TX 79014 | Oil & Gas Operator | Feb 2026 |
| 614 | Upstream Properties, LLC | Southlake, TX 76092 | Oil & Gas Operator | Feb 2026 |
| 615 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 616 | Vaca Operating Company LLC | Pacific PLSDS, CA 90272 | Oil & Gas Operator | Aug 2017 |
| 617 | Valera Oil Company | Kingsland, TX 78639 | Oil & Gas Operator | Apr 2000 |
| 618 | Valley Petroleum Company | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 619 | Vanco Oil & Gas Corp. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 620 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 621 | Vanguard Permian, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 622 | Viathon Hydrocarbons, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Oct 2020 |
| 623 | Victory Oil & Gas Inc | Gun Barrel Cy, TX 75156 | Oil & Gas Operator | Feb 2026 |
| 624 | Vortt Exploration Company, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2019 |
| 625 | Wagman Petroleum, Inc. | Dallas, TX 75202 | Oil & Gas Operator | Feb 2026 |
| 626 | Wagman, Brent A. | Dallas, TX 75202 | Oil & Gas Operator | Feb 2026 |
| 627 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Feb 2026 |
| 628 | Walsh Resources, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Feb 2026 |
| 629 | Warren Producers Inc | Bowling Green, KY 42102 | Oil & Gas Operator | Dec 2017 |
| 630 | Watco Energy, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Apr 1996 |
| 631 | Wells Oilfield Services, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 632 | Wellstar Corporation | Northglenn, CO 80233 | Oil & Gas Operator | Dec 2025 |
| 633 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 634 | Western Pride Resources, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Jan 2011 |
| 635 | Western Sky Oil & Gas | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 636 | Westico Energy Co. | Abilene, TX 79605 | Oil & Gas Operator | Nov 2004 |
| 637 | Westwood Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | May 2013 |
| 638 | WG Operating, Inc. | Tulsa, OK 74153 | Oil & Gas Operator | May 2012 |
| 639 | White, Frank | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 640 | Whiteside, H. W. | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 641 | Wilbanks, Bruce A. Company | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 642 | Willowbend Investments, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 643 | Wilson, WM. B. Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 1996 |
| 644 | Winchester Energy Operating Co. | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 645 | Winchester Production Co., LTD. | Shreveport, LA 71129 | Oil & Gas Operator | Sep 2008 |
| 646 | Windham Resources | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 647 | Windham Resources, Inc. | Tuscola, TX 79562 | Oil & Gas Operator | Feb 2004 |
| 648 | Window Operating Co., The | Coleman, TX 76834 | Oil & Gas Operator | Feb 2026 |
| 649 | Wishbone Texas Operating Co LLC | Houston, TX 77064 | Oil & Gas Operator | Jul 2019 |
| 650 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Feb 2026 |
| 651 | Wolcott, Ed Operating | Dallas, TX 75205 | Oil & Gas Operator | Oct 2000 |
| 652 | Woodbine Petroleum, Inc. | Dallas, TX 75204 | Oil & Gas Operator | Aug 2003 |
| 653 | Woodygreen Resources, LLC | Plano, TX 75093 | Oil & Gas Operator | Feb 2026 |
| 654 | Woodygreen Resources, LP | Abilene, TX 79608 | Oil & Gas Operator | Mar 2012 |
| 655 | World Producers, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1994 |
| 656 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 657 | Xophi Energy, LLC | Arlington, TX 76006 | Oil & Gas Operator | Feb 2026 |
| 658 | Ziegler-Peru, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 2019 |
| 659 | Zzron Inc. | Midland, TX 79704 | Oil & Gas Operator | Aug 2003 |