| 601 | Whitt, W. J. | Albany, TX 76430 | Oil & Gas Operator | Nov 1996 |
| 602 | Wilbanks, Bruce A. | Midland, TX 79701 | Oil & Gas Operator | Aug 1996 |
| 603 | Wilbrook Exploration, Inc. | Lingleville, TX 76461 | Oil & Gas Operator | Aug 2003 |
| 604 | Williams Deville Operating, Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Sep 2026 |
| 605 | Wimsco, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1994 |
| 606 | Winco Oil Inc. | Abilene, TX 79608 | Oil & Gas Operator | Sep 2026 |
| 607 | Winfrey Oil Co., Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2016 |
| 608 | Winn Exploration Co., Inc. | Corpus Christ, TX 78401 | Oil & Gas Operator | Sep 2026 |
| 609 | WM Wild Wolf Production LLC | Albany, TX 76430 | Oil Operator | Sep 2026 |
| 610 | Xophi Energy, LLC | Arlington, TX 76006 | Oil & Gas Operator | Sep 2026 |
| 611 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |
| 612 | Yeates, F. L. | Breckenridge, TX 76424 | Oil & Gas Operator | Oct 1997 |
| 613 | Yellow Rose Oil & Gas Oper. Inc. | Cisco, TX 76437 | Oil & Gas Operator | Sep 2026 |
| 614 | Yellow Rose Oil & Gas Operating | Cisco, TX 76437 | Oil & Gas Operator | Jan 1996 |
| 615 | Young, L. M. | Brownwood, TX 76804 | Oil & Gas Operator | Aug 2003 |
| 616 | Young, Marshall R., Oil Co. | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |