| 401 | Trans Terra Corp., International | Amarillo, TX 79159 | Oil & Gas Operator | Feb 2009 |
| 402 | Travelers Oil Company | Amarillo, TX 79102 | Oil & Gas Operator | Dec 2024 |
| 403 | Trojan Oil And Gas | White Deer, TX 79097 | Oil & Gas Operator | Dec 1994 |
| 404 | Tryma Operating | Borger, TX 79008 | Oil & Gas Operator | Dec 2024 |
| 405 | TTL Energy Resources, Inc. | Borger, TX 79008 | Oil & Gas Operator | Aug 2013 |
| 406 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 407 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 408 | Untamed Resources, LLC | Spearman, TX 79081 | Gas Operator | Dec 2024 |
| 409 | Upland Resources LLC | Canadian, TX 79014 | Oil & Gas Operator | Dec 2024 |
| 410 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Dec 2024 |
| 411 | Valero Marketing & Supply Co | San Antonio, TX 78269-6000 | Oil & Gas Operator | Sep 2023 |
| 412 | Vitol Inc | Houston, TX 77002 | Oil & Gas Operator | Sep 2023 |
| 413 | VRK Oil And Gas, Inc. | Arlington, TX 76016 | Oil & Gas Operator | Mar 2014 |
| 414 | W. B. D. Oil & Gas Company | Pampa, TX 79066 | Oil & Gas Operator | Dec 1995 |
| 415 | W.B.D. Oil And Gas Inc. | Pampa, TX 79066 | Oil & Gas Operator | Oct 2019 |
| 416 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2024 |
| 417 | Walls, G. M. & Frances, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Dec 2024 |
| 418 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Dec 2024 |
| 419 | Watkins, J. B. | Borger, TX 79007 | Oil & Gas Operator | May 2009 |
| 420 | Watson Operating Company | Pampa, TX 79066 | Oil & Gas Operator | Dec 2003 |
| 421 | Wellstar Corporation | Northglenn, CO 80233 | Oil & Gas Operator | Oct 2024 |
| 422 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Oct 2024 |
| 423 | WG Operating, Inc. | Tulsa, OK 74153 | Oil & Gas Operator | May 2012 |
| 424 | Wheeler Oil Co. (A) | Amarillo, TX 79114 | Gas Operator | Apr 2001 |
| 425 | Whitlock, J.R. Operator | Amarillo, TX 79105 | Gas Operator | Jul 1997 |
| 426 | Whittington, G. R. | Amarillo, TX 79109 | Oil & Gas Operator | Jan 1994 |
| 427 | Whittington, G. R. Estate | Amarillo, TX 79109 | Oil & Gas Operator | Mar 2008 |
| 428 | Wilbanks Exploration, Inc. | Denver, CO 80202 | Oil & Gas Operator | May 2002 |
| 429 | Wilco Properties, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jan 2004 |
| 430 | Winchester Oil & Gas LLC | Rockdale, TX 76567 | Oil Operator | Dec 2024 |
| 431 | Wischkaemper, Kenneth | Shamrock, TX 79079 | Oil & Gas Operator | Dec 2024 |
| 432 | Wo Operating Company | Tulsa, OK 74159 | Oil & Gas Operator | Dec 2024 |
| 433 | Wylie, Fred, Jr. | Moran, TX 76464 | Oil & Gas Operator | Oct 2022 |
| 434 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Dec 2024 |