| 501 | Star One Energy, Inc. | Fort Worth, TX 76163 | Oil & Gas Operator | May 2012 |
| 502 | Stasney, H. R. & Sons, LTD. | Albany, TX 76430 | Oil & Gas Operator | Apr 2026 |
| 503 | STB Energy Inc. | Tulsa, OK 74105 | Oil & Gas Operator | Jul 2008 |
| 504 | Stealth, Inc. | Cross Plains, TX 76443 | Gas Operator | Mar 1997 |
| 505 | Stellex | De Leon, TX 76444 | Oil & Gas Operator | Apr 2026 |
| 506 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2026 |
| 507 | Stephenson Oil & Gas, Inc. | Eastland, TX 76448 | Oil & Gas Operator | Sep 1999 |
| 508 | Sterling Oil And Gas | Weatherford, TX 76086 | Oil & Gas Operator | Apr 2026 |
| 509 | Stewart Family Holdings LLC | Weatherford, TX 76087 | Oil & Gas Operator | Apr 2026 |
| 510 | Stewart, James G. | Graham, TX 76450 | Oil & Gas Operator | Sep 2019 |
| 511 | Stober Oil And Gas Services, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2026 |
| 512 | Stovall, Howard | Cisco, TX 76437 | Oil & Gas Operator | Apr 2026 |
| 513 | Stowe Energy, Inc. | Vernon, TX 76384 | Oil & Gas Operator | Mar 2003 |
| 514 | Stream Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 515 | Subsurface Energy Corp. | Coleman, TX 76834 | Oil & Gas Operator | Apr 2026 |
| 516 | Sun-Key Oil Co., Inc. | Dublin, TX 76446 | Oil & Gas Operator | Apr 2026 |
| 517 | Sunbelt Salvage | Eastland, TX 76448 | Oil & Gas Operator | Sep 1998 |
| 518 | Sundance Resources, Inc. | Rio VIsta, TX 76093 | Oil & Gas Operator | Mar 2012 |
| 519 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2026 |
| 520 | Sweetwater Drilling Co., Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2026 |
| 521 | T & S Oil & Gas, LLC | Graham, TX 76450 | Gas Operator | Apr 2026 |
| 522 | T-Square Petroleum Co. | Rising Star, TX 76471 | Oil & Gas Operator | Apr 2026 |
| 523 | T. L. J. Incorporated | Big Lake, TX 76932 | Oil & Gas Operator | Dec 1998 |
| 524 | T.L.S. Oil Co. | Hawley, TX 79525 | Oil & Gas Operator | Apr 2026 |
| 525 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 526 | Tandem Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Apr 2026 |
| 527 | Targo Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2026 |
| 528 | Taylor Oil & Gas Serv | Snyder, TX 79549 | Oil Operator | Apr 2026 |
| 529 | TCF Energy, Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 530 | Teaco | Snyder, TX 79550 | Oil & Gas Operator | Jan 1998 |
| 531 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2026 |
| 532 | Terrick Resources | Midland, TX 79708 | Oil & Gas Operator | Jul 2005 |
| 533 | Tex-Am Petroleum Corp. | Eastland, TX 76448 | Oil & Gas Operator | Apr 2026 |
| 534 | Tex-Ann Oil & Gas Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2026 |
| 535 | Texas State Oil Co. | Irving, TX 75062 | Oil & Gas Operator | Mar 2017 |
| 536 | Texas United Geoproduction, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Apr 2026 |
| 537 | Texdon Operating | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2005 |
| 538 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Apr 2026 |
| 539 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Apr 2026 |
| 540 | Thrifty Well Service | Rice, TX 75155 | Oil & Gas Operator | Jun 2009 |
| 541 | THT Covenant Holdings, LLC | Henrietta, TX 76365 | Oil Operator | Apr 2026 |
| 542 | Tice, Robin Alejandrina | Gordon, TX 76453 | Gas Operator | Apr 2026 |
| 543 | Tidwell Production Company | Sonora, TX 76950 | Oil & Gas Operator | Apr 2026 |
| 544 | TK Operating | Cross Plains, TX 76443 | Oil & Gas Operator | Apr 2026 |
| 545 | Todd, J R Oil & Investments, Inc | Dallas, TX 75206 | Oil & Gas Operator | Jun 2002 |
| 546 | Torch Operating LLC | Fort Worth, TX 76135 | Oil & Gas Operator | Oct 2020 |
| 547 | Trace Energy Management Inc | Weatherford, TX 76086 | Oil & Gas Operator | Apr 2026 |
| 548 | Tracer Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2026 |
| 549 | Transcontinental Shale L.L.C. | Austin, TX 78717 | Oil & Gas Operator | Feb 2016 |
| 550 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Apr 2026 |
| 551 | Tri Sportsmen Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Apr 2026 |
| 552 | Triple Singleton, Inc. | Santa Fe, TX 77510 | Oil & Gas Operator | Dec 2020 |
| 553 | Trumter Petroleum Corporation | Fort Worth, TX 76185 | Oil & Gas Operator | Aug 1998 |
| 554 | Tuckco Petroleum Corporation | Andrews, TX 79714 | Oil & Gas Operator | Feb 2026 |
| 555 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 556 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 557 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | Apr 2026 |
| 558 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2026 |
| 559 | Valley Petroleum Company | Abilene, TX 79608 | Oil & Gas Operator | Apr 2026 |
| 560 | Van Operating, LTD. | Albany, TX 76430 | Oil & Gas Operator | Apr 2026 |
| 561 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 562 | Vanguard Permian, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 563 | Verado Energy, Inc. | Allen, TX 75013 | Oil & Gas Operator | Oct 2025 |
| 564 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Apr 2026 |
| 565 | Vortt Exploration Company, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2019 |
| 566 | Walter Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | May 2009 |
| 567 | Watson Oil & Gas Co. | Gorman, TX 76454 | Oil & Gas Operator | Jan 2002 |
| 568 | Watson Oil & Gas, Inc. | Spicewood, TX 78669 | Oil & Gas Operator | Apr 2026 |
| 569 | Weakland Investments, Inc. | Denver, CO 80215 | Oil & Gas Operator | Apr 2026 |
| 570 | Wehunt Oil Company, Inc. | Dallas, TX 75376 | Oil & Gas Operator | Nov 2002 |
| 571 | Wejco, Inc. | Rising Star, TX 76471 | Oil & Gas Operator | Apr 2026 |
| 572 | Welcome Well Serv. & Boykin Bros | Abilene, TX 79604 | Oil & Gas Operator | Apr 1995 |
| 573 | Wells Oilfield Services, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2026 |
| 574 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 575 | West Texas Royalties, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2026 |
| 576 | Western Chief Oil & Gas Company | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 577 | Western Gulf Oil & Gas Inc. | Dallas, TX 75360 | Oil & Gas Operator | Jul 2000 |
| 578 | Western Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2026 |
| 579 | Wheat, Buck Resources, Inc. | Eastland, TX 76448 | Oil & Gas Operator | Dec 2009 |
| 580 | Whiteside, Robert | Comanche, TX 76442 | Oil & Gas Operator | May 1998 |
| 581 | Whitt, W. J. | Albany, TX 76430 | Oil & Gas Operator | Nov 1996 |
| 582 | Wilbanks, Bruce A. | Midland, TX 79701 | Oil & Gas Operator | Aug 1996 |
| 583 | Wilbrook Exploration, Inc. | Lingleville, TX 76461 | Oil & Gas Operator | Aug 2003 |
| 584 | Wilchar, DR. R. B. | Fort Worth, TX 76185 | Oil & Gas Operator | Jan 2007 |
| 585 | Wilson Well Service Inc. | Cross Plains, TX 76443 | Oil & Gas Operator | Apr 2026 |
| 586 | Wilson, Jerry L. | Ranger, TX 76470 | Oil & Gas Operator | Apr 2026 |
| 587 | Wilson, Olan Max | Cisco, TX 76437 | Oil & Gas Operator | Apr 2026 |
| 588 | Wilson, WM. B. Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 1996 |
| 589 | Window Operating Co., The | Coleman, TX 76834 | Oil & Gas Operator | Apr 2026 |
| 590 | Wineridge Inc. | Austin, TX 78747 | Oil Operator | Apr 2026 |
| 591 | Wise Production Company | Bowie, TX 76230 | Oil & Gas Operator | Apr 2026 |
| 592 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Apr 2026 |
| 593 | World Producers, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1994 |
| 594 | Wright Oil And Gas, LLC | Benbrook, TX 76126 | Oil & Gas Operator | Apr 2026 |
| 595 | Xeric Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 596 | Xplore Operating, LLC | Arlington, TX 76001 | Oil & Gas Operator | Apr 2026 |
| 597 | Yellow Rose Oil & Gas Oper. Inc. | Cisco, TX 76437 | Oil & Gas Operator | Apr 2026 |
| 598 | Yellow Rose Oil & Gas Operating | Cisco, TX 76437 | Oil & Gas Operator | Jan 1996 |
| 599 | Young, L. M. | Brownwood, TX 76804 | Oil & Gas Operator | Aug 2003 |