| 401 | Seay Oil & Gas, LTD. | Dripping SPGS, TX 78620 | Oil & Gas Operator | Apr 2013 |
| 402 | Sedco Resources Inc | Kerrville, TX 78029 | Oil & Gas Operator | Apr 2025 |
| 403 | Seeker Oil Company, Incorporated | San Antonio, TX 78209 | Oil & Gas Operator | Apr 2025 |
| 404 | Seguro Well Service, Inc. | Gonzales, TX 78629 | Oil & Gas Operator | Apr 2025 |
| 405 | Sei Operating, LLC | Mandeville, LA 70471 | Oil & Gas Operator | Apr 2025 |
| 406 | Sellers Lease Service, Inc. | Flatonia, TX 78941 | Oil & Gas Operator | Apr 2025 |
| 407 | Shell Trading Us Company | Houston, TX 77210 | Oil & Gas Operator | Jan 2025 |
| 408 | Sinclair Energy Corporation | Fort Worth, TX 76177 | Oil & Gas Operator | Apr 2025 |
| 409 | Slingshot Oil & Gas | Houston, TX 77019 | Oil Operator | Apr 2025 |
| 410 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Apr 2025 |
| 411 | Source Petroleum Inc. | San Antonio, TX 78265 | Oil & Gas Operator | Apr 2025 |
| 412 | Southwest Gas Systems, Inc. | Spring, TX 77379 | Oil & Gas Operator | Apr 2025 |
| 413 | Southwest Land & Minerals, Inc. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Aug 2003 |
| 414 | Spencer-Cloughly Investments Inc | San Marcos, TX 78666 | Oil & Gas Operator | Aug 2002 |
| 415 | Spur Operating Co. | Austin, TX 78701 | Oil & Gas Operator | Apr 2025 |
| 416 | Statia Enterprises, Inc | Irving, TX 75014 | Oil & Gas Operator | Apr 2025 |
| 417 | Steindorf, Bert Oil & Gas Co. | Floresville, TX 78114 | Oil & Gas Operator | Apr 2025 |
| 418 | Steller Energy & Investment Corp | Plano, TX 75093 | Oil & Gas Operator | Feb 2021 |
| 419 | Stoneburner Exploration, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Oct 1997 |
| 420 | Stonegate Operators, Inc. | Addison, TX 75001 | Oil Operator | Apr 2025 |
| 421 | Story NRG LLC | Boerne, TX 78006 | Oil & Gas Operator | Apr 2025 |
| 422 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 423 | Stratco Operating Co Inc | Austin, TX 78701 | Oil & Gas Operator | Apr 2025 |
| 424 | Struthoff Energy, L.L.C. | San Antonio, TX 78216 | Oil Operator | Apr 2025 |
| 425 | Sue-Ann Production Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 426 | Sunburst, Inc. | Wheat Ridge, CO 80033 | Oil & Gas Operator | Feb 2025 |
| 427 | Sure Flow Oil & Gas, Inc. | Victoria, TX 77902 | Oil & Gas Operator | Apr 2025 |
| 428 | Swiess & Thomas | San Antonio, TX 78247 | Oil Operator | Apr 2025 |
| 429 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 430 | Syj Oil & Gas | San Antonio, TX 78209 | Oil Operator | Sep 2000 |
| 431 | Syj Oil & Gas, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Apr 2025 |
| 432 | Sylvan Energy, LLC | Pittsburgh, PA 15211 | Oil & Gas Operator | Apr 2025 |
| 433 | Symba American Oil, Inc | Houston, TX 77056 | Oil Operator | Apr 2025 |
| 434 | T & T Oil Co. | San Antonio, TX 78205 | Oil & Gas Operator | Dec 2002 |
| 435 | Tag Oil | La Vernia, TX 78121 | Oil Operator | Apr 2025 |
| 436 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 437 | Tanglehead Operating, LLC | La Vernia, TX 78121 | Oil Operator | Apr 2025 |
| 438 | Tanglewood Oil & Gas Co. | Gouldbusk, TX 76845 | Oil & Gas Operator | Apr 2025 |
| 439 | Tanos Production, Inc. | Houston, TX 77077 | Oil & Gas Operator | Aug 2003 |
| 440 | Tejones Operating Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Apr 2025 |
| 441 | Terra Locus Services | Seguin, TX 78155 | Oil & Gas Operator | Jun 2000 |
| 442 | Texas Coastal Resources LLC | Fairhope, AL 36532 | Oil Operator | Apr 2025 |
| 443 | Texas South Operating Co, Inc. | Houston, TX 77027 | Oil Operator | Apr 2025 |
| 444 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 445 | Texas, Les & Co. | Austin, TX 78746 | Oil & Gas Operator | Apr 2025 |
| 446 | Texcal Oil Co | Cuero, TX 77954 | Oil & Gas Operator | Feb 2006 |
| 447 | Texlark Exploration Company, Inc | Plano, TX 75074 | Oil & Gas Operator | Sep 2001 |
| 448 | Texokan Operating, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Apr 2025 |
| 449 | Texstar Drilling, Inc. | Houston, TX 77084 | Oil & Gas Operator | Apr 2025 |
| 450 | Texstar Oil & Gas, LLC | Luling, TX 78648 | Oil & Gas Operator | Apr 2025 |
| 451 | Thomas Oil & Gas Company | Luling, TX 78648 | Oil & Gas Operator | Aug 2003 |
| 452 | Thomas, T. N. Oil Company | Aiken, SC 29801 | Oil & Gas Operator | Apr 2025 |
| 453 | Thorp Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2014 |
| 454 | Three J Energy, Inc. | Seguin, TX 78155 | Oil & Gas Operator | Apr 2025 |
| 455 | Tidal Petroleum, Inc. | Schertz, TX 78154 | Oil & Gas Operator | Apr 2025 |
| 456 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 457 | Titan Exploration LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2025 |
| 458 | Tiza Energy, Inc. | Austin, TX 78715 | Oil & Gas Operator | Apr 2025 |
| 459 | Tiza Operating Company | Austin, TX 78716 | Oil & Gas Operator | Jan 2000 |
| 460 | TK Drilling Corp. | Tulsa, OK 74133 | Oil & Gas Operator | Jan 2025 |
| 461 | Tri-County Operating Company | Seguin, TX 78156 | Gas Operator | Feb 1997 |
| 462 | Trident Corporation | Woodsboro, TX 78393 | Oil & Gas Operator | Apr 2025 |
| 463 | Trinity Operating (Usg), LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 464 | Triple H Production | Stockdale, TX 78160 | Oil Operator | Apr 2025 |
| 465 | Trivista Operating LLC | Giddings, TX 78942 | Oil & Gas Operator | Apr 2025 |
| 466 | Truth Resources LP | Houston, TX 77090 | Oil Operator | Sep 2021 |
| 467 | Tucker Operating Co., Inc. | Victoria, TX 77903 | Oil & Gas Operator | Apr 2025 |
| 468 | Tularosa Operating Company | Kerrville, TX 78029 | Oil & Gas Operator | Mar 2024 |
| 469 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Apr 2025 |
| 470 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 471 | United Oil & Minerals L. P. | Austin, TX 78746 | Oil & Gas Operator | Jun 2003 |
| 472 | United Oil & Minerals, Inc. | Austin, TX 78746 | Oil & Gas Operator | Jan 2001 |
| 473 | Upland Operating, LLC | Dallas, TX 75226 | Oil & Gas Operator | Apr 2025 |
| 474 | Valero Marketing & Supply Co | San Antonio, TX 78269-6000 | Oil & Gas Operator | Sep 2023 |
| 475 | Van Winkle Oil | Floresville, TX 78114 | Oil & Gas Operator | Apr 2025 |
| 476 | Venado Operating Company LLC | Austin, TX 78738 | Oil & Gas Operator | Mar 2022 |
| 477 | Viola Prod., Inc. | Dallas, TX 75251 | Oil & Gas Operator | Apr 2025 |
| 478 | Viper S.W.D., LLC | El Campo, TX 77437 | Oil & Gas Operator | Apr 2025 |
| 479 | Virtex Operating Company, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2023 |
| 480 | Virtex Petroleum Company, Inc. | Corpus Chrsti, TX 78477 | Oil & Gas Operator | Jan 2008 |
| 481 | Vistar Oil Texas LLC | Friendswood, TX 77546 | Oil Operator | Jan 2017 |
| 482 | Vomela Resources Inc. | Flatonia, TX 78941 | Oil & Gas Operator | Apr 2025 |
| 483 | W.W. Energy | Luling, TX 78648 | Oil & Gas Operator | Apr 2025 |
| 484 | Wainoco Oil & Gas Company | Houston, TX 77024 | Oil & Gas Operator | Dec 2005 |
| 485 | Walker, Daniel J. | La Vernia, TX 78121 | Oil Operator | Apr 2025 |
| 486 | Walker, Harrel L. | La Vernia, TX 78121 | Oil & Gas Operator | May 2023 |
| 487 | Warwick-Artemis, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Apr 2025 |
| 488 | Watco Energy, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Apr 1996 |
| 489 | WCS Oil & Gas Corporation | Dallas, TX 75209 | Oil & Gas Operator | Aug 2021 |
| 490 | Wen-Be | Jourdanton, TX 78026 | Oil & Gas Operator | Apr 2025 |
| 491 | Westridge Oil & Gas Properties | Mineral Wells, TX 76068 | Oil & Gas Operator | Apr 2025 |
| 492 | Wilbrook Exploration, Inc. | Lingleville, TX 76461 | Oil & Gas Operator | Aug 2003 |
| 493 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Apr 2025 |
| 494 | Winn Exploration Co., Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2025 |
| 495 | Wolfe Oil Company | Stockdale, TX 78160 | Oil Operator | Apr 2025 |
| 496 | WRD Oil, LLC | Floresville, TX 78114 | Oil & Gas Operator | Apr 2025 |
| 497 | Wright Brothers Energy, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Apr 2025 |
| 498 | WSM | New Braunfels, TX 78132 | Oil Operator | Apr 2025 |
| 499 | WTXR Operating (Texas), Inc. | Carrollton, TX 75007 | Oil Operator | Apr 2025 |
| 500 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |