| 601 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 602 | West Texas Royalties, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 603 | Western Chief Oil & Gas Company | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 604 | Western Gulf Oil & Gas Inc. | Dallas, TX 75360 | Oil & Gas Operator | Jul 2000 |
| 605 | Western Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 606 | Wheat, Buck Resources, Inc. | Eastland, TX 76448 | Oil & Gas Operator | Dec 2009 |
| 607 | Whiteside, Robert | Comanche, TX 76442 | Oil & Gas Operator | May 1998 |
| 608 | Whitt, W. J. | Albany, TX 76430 | Oil & Gas Operator | Nov 1996 |
| 609 | Whittington, James C., Inc. | Dallas, TX 75214 | Oil & Gas Operator | Jan 2017 |
| 610 | Wilbanks, Bruce A. | Midland, TX 79701 | Oil & Gas Operator | Aug 1996 |
| 611 | Wilbrook Exploration, Inc. | Lingleville, TX 76461 | Oil & Gas Operator | Aug 2003 |
| 612 | Wilchar, DR. R. B. | Fort Worth, TX 76185 | Oil & Gas Operator | Jan 2007 |
| 613 | Williamson, Harry W. Inc. | Abilene, TX 79604 | Oil & Gas Operator | May 1995 |
| 614 | Wilson Well Service Inc. | Cross Plains, TX 76443 | Oil & Gas Operator | Feb 2026 |
| 615 | Wilson, Jerry L. | Ranger, TX 76470 | Oil & Gas Operator | Feb 2026 |
| 616 | Wilson, Olan Max | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 617 | Wilson, WM. B. Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 1996 |
| 618 | Window Operating Co., The | Coleman, TX 76834 | Oil & Gas Operator | Feb 2026 |
| 619 | Wineridge Inc. | Austin, TX 78747 | Oil Operator | Feb 2026 |
| 620 | Wise Production Company | Bowie, TX 76230 | Oil & Gas Operator | Feb 2026 |
| 621 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Feb 2026 |
| 622 | World Producers, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 1994 |
| 623 | Wright Oil And Gas, LLC | Benbrook, TX 76126 | Oil & Gas Operator | Feb 2026 |
| 624 | Xeric Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 625 | Xplore Operating, LLC | Arlington, TX 76001 | Oil & Gas Operator | Feb 2026 |
| 626 | Yellow Rose Oil & Gas Oper. Inc. | Cisco, TX 76437 | Oil & Gas Operator | Feb 2026 |
| 627 | Yellow Rose Oil & Gas Operating | Cisco, TX 76437 | Oil & Gas Operator | Jan 1996 |
| 628 | Young, L. M. | Brownwood, TX 76804 | Oil & Gas Operator | Aug 2003 |