| 401 | Tara Company, The | Wichita Falls, TX 76301 | Oil Operator | Sep 2003 |
| 402 | Taylor, J. S. Inc. | Lewisville, TX 75057 | Oil & Gas Operator | Feb 2026 |
| 403 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 404 | Teal Exploration, LLC | Abilene, TX 79602 | Oil Operator | Feb 2026 |
| 405 | Tex-Ann Oil & Gas Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 406 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Feb 2026 |
| 407 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 408 | Texas Pharchem Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2019 |
| 409 | Texas State Oil Co. | Irving, TX 75062 | Oil & Gas Operator | Mar 2017 |
| 410 | Texas United Geoproduction, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Feb 2026 |
| 411 | Texland-Rector & Schumacher | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2000 |
| 412 | Texoma Oil Tools, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 413 | Texzona Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1997 |
| 414 | Three Rivers Operating Co LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 415 | Threshold Exploration, Inc. | College Sta, TX 77842 | Oil & Gas Operator | Oct 2015 |
| 416 | Tipperary Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 417 | Titan Energy, Inc. | Austin, TX 78703 | Oil & Gas Operator | Feb 2026 |
| 418 | TKP Petroleum, Inc. | Lubbock, TX 79464 | Oil & Gas Operator | Feb 2026 |
| 419 | Tollett Oil | Graham, TX 76450 | Oil Operator | Nov 2024 |
| 420 | Townsend Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2021 |
| 421 | Tracer Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 422 | Tri Sportsmen Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 423 | Trio Consulting & Management,LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 424 | Triple J Investments Inc | Longview, TX 75606 | Oil & Gas Operator | Feb 2023 |
| 425 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 426 | Veneto Exploration, LLC | Richardson, TX 75083 | Oil & Gas Operator | Feb 2026 |
| 427 | Vin Fisher Operating, Inc. | Andrews, TX 79714 | Oil & Gas Operator | Feb 2026 |
| 428 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Feb 2026 |
| 429 | Vista Energy Corp. | Good Lettsvle, TN 37072 | Oil & Gas Operator | Feb 2026 |
| 430 | Vortt Exploration Company, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2019 |
| 431 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Feb 2026 |
| 432 | Walter Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | May 2009 |
| 433 | Walton Producing Company | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2005 |
| 434 | Walton Producing Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 435 | WBR, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 1995 |
| 436 | Weakland Investments, Inc. | Denver, CO 80215 | Oil & Gas Operator | Feb 2026 |
| 437 | Weaver Global Operating, LLC | Colleyville, TX 76034 | Oil Operator | Feb 2026 |
| 438 | Wes-Mor Drilling, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 439 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 440 | Western Chief Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 441 | Western Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 442 | Western Sky Oil & Gas | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 443 | Westico Energy Co. | Abilene, TX 79605 | Oil & Gas Operator | Nov 2004 |
| 444 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 445 | Westwood Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | May 2013 |
| 446 | WG Oil, LLC | Wichita Falls, TX 76308 | Oil Operator | Feb 2026 |
| 447 | WG Operating, Inc. | Tulsa, OK 74153 | Oil & Gas Operator | May 2012 |
| 448 | Wheeler Operating Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Feb 2026 |
| 449 | Wilco Properties, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jan 2004 |
| 450 | Wilcox Energy Company LLC | Rule, TX 79547 | Oil & Gas Operator | Feb 2026 |
| 451 | Wilcox Oil Company | Rule, TX 79547 | Oil & Gas Operator | Aug 2008 |
| 452 | Wilcox Petroleum Operating LLC. | Rule, TX 79547 | Oil & Gas Operator | Feb 2026 |
| 453 | Williams Deville Operating, Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Feb 2026 |
| 454 | Williams Oil Company | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 455 | Willowbend Investments, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 456 | Wingrove Operating, LLC | Odessa, TX 79760 | Oil Operator | Feb 2026 |
| 457 | Wingrove Well Service, Inc. | Lueders, TX 79533 | Oil & Gas Operator | Nov 2023 |
| 458 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 459 | Wortham, E. H. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 460 | Xophi Energy, LLC | Arlington, TX 76006 | Oil & Gas Operator | Feb 2026 |
| 461 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 462 | Yeti Exploration, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Feb 2026 |
| 463 | Young Marshall R Oil Co | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 464 | Young, L. M. | Brownwood, TX 76804 | Oil & Gas Operator | Aug 2003 |