| 401 | Thrifty Well Service | Rice, TX 75155 | Oil & Gas Operator | Jun 2009 |
| 402 | Thunderbird Operating, L.L.C. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 403 | TNT Energy Inc. | Brownwood, TX 76801 | Oil & Gas Operator | May 2013 |
| 404 | Tom-Tom Operating, LLC | Dallas, TX 75209 | Oil & Gas Operator | Dec 2025 |
| 405 | Tomco Oil & Gas Inc. | Comanche, TX 76442 | Oil & Gas Operator | Dec 2025 |
| 406 | Torch Operating LLC | Fort Worth, TX 76135 | Oil & Gas Operator | Oct 2020 |
| 407 | TPC Exploration, LLC | May, TX 76857 | Oil & Gas Operator | Dec 2025 |
| 408 | Tri Energy Resources, Inc. | Norman, OK 73070 | Oil Operator | Dec 2025 |
| 409 | Triple D Oil & Gas Co., Inc. | Brownwood, TX 76801 | Oil & Gas Operator | Dec 2025 |
| 410 | Tritex Resources, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2009 |
| 411 | Trust Oil Co. | Pine, CO 80470 | Oil & Gas Operator | Dec 2025 |
| 412 | Trustar Operating Company Inc. | Austin, TX 78750 | Oil Operator | Dec 2025 |
| 413 | Turner, Greg | Cross Plains, TX 76443 | Oil & Gas Operator | Dec 2025 |
| 414 | Txon Partners, LLC | Houston, TX 77057 | Oil & Gas Operator | Jun 2017 |
| 415 | Upp Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 416 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2025 |
| 417 | Valley Petroleum Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2025 |
| 418 | W.O.G., Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 419 | W.W.R. Holding, LLC | Coleman, TX 76834 | Oil & Gas Operator | Mar 2008 |
| 420 | Wagner, Duer & Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Jan 1999 |
| 421 | Walker Oil & Gas | Early, TX 76802 | Oil & Gas Operator | Dec 2002 |
| 422 | Ward Trust | Spring, TX 77383 | Oil & Gas Operator | May 2013 |
| 423 | WCT Leasing Co. | Austin, TX 78734 | Oil & Gas Operator | Apr 2019 |
| 424 | Weaver Global Operating, LLC | Colleyville, TX 76034 | Oil Operator | Dec 2025 |
| 425 | Wejco, Inc. | Rising Star, TX 76471 | Oil & Gas Operator | Dec 2025 |
| 426 | Wes-Tex Oil Co. (I) | Bangs, TX 76823 | Oil & Gas Operator | Dec 2025 |
| 427 | West Texas Diversified Interests | Eastland, TX 76448 | Oil & Gas Operator | Jun 2006 |
| 428 | West Texas Royalties, Inc. | Graham, TX 76450 | Oil & Gas Operator | Dec 2025 |
| 429 | Weststar Operating Company | Santa Anna, TX 76878 | Oil & Gas Operator | Mar 2015 |
| 430 | WG Operating, Inc. | Tulsa, OK 74153 | Oil & Gas Operator | May 2012 |
| 431 | White Knight Production LLC | Lafayette, LA 70505 | Oil & Gas Operator | Feb 2024 |
| 432 | White, Oscar | Tuscola, TX 79562 | Oil & Gas Operator | Dec 2025 |
| 433 | Whitehead Prod. Co., Inc. | Humble, TX 77338 | Oil & Gas Operator | Sep 2025 |
| 434 | Whitt, W. J. | Albany, TX 76430 | Oil & Gas Operator | Nov 1996 |
| 435 | Wilbrook Exploration, Inc. | Lingleville, TX 76461 | Oil & Gas Operator | Aug 2003 |
| 436 | Willowbend Investments, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2025 |
| 437 | Wilson Energy Resources LLC | Graham, TX 76450 | Oil Operator | Dec 2025 |
| 438 | Wilson Well Service Inc. | Cross Plains, TX 76443 | Oil & Gas Operator | Dec 2025 |
| 439 | Wilson, Olan Max | Cisco, TX 76437 | Oil & Gas Operator | Dec 2025 |
| 440 | Window Operating Co., The | Coleman, TX 76834 | Oil & Gas Operator | Dec 2025 |
| 441 | WJH Energy, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2025 |
| 442 | Wortham, E. H. | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 443 | Wylie Bros. Prod. & DRGL. Co,Inc | Baird, TX 79504 | Oil & Gas Operator | Dec 2025 |
| 444 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 445 | Xhorizons Energy LLC | Houston, TX 77079 | Oil Operator | Dec 2025 |
| 446 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 447 | Xplore Operating, LLC | Arlington, TX 76001 | Oil & Gas Operator | Dec 2025 |
| 448 | Xta Resources LLC | Uvalde, TX 78801 | Oil & Gas Operator | Dec 2025 |
| 449 | Xtreme Operating Company LLC | Flower Mound, TX 75022 | Oil Operator | Dec 2025 |
| 450 | Yellow Rose Oil & Gas Oper. Inc. | Cisco, TX 76437 | Oil & Gas Operator | Dec 2025 |
| 451 | Yellow Rose Oil & Gas Operating | Cisco, TX 76437 | Oil & Gas Operator | Jan 1996 |
| 452 | Young, L. M. | Brownwood, TX 76804 | Oil & Gas Operator | Aug 2003 |
| 453 | Ziegler-Peru, Inc. | Houston, TX 77027 | Oil & Gas Operator | Dec 2019 |
| 454 | Zoe Oil & Energy, LP | Fort Worth, TX 76148 | Oil & Gas Operator | Dec 2025 |