| 601 | U S Energy Corp. Of Amer. Inc. | Cisco, TX 76437 | Oil & Gas Operator | Jun 2026 |
| 602 | Uhc Petroleum Corporation | Rocksprings, TX 78880 | Oil & Gas Operator | Jun 2026 |
| 603 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 604 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 605 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jun 2026 |
| 606 | United Company | Lubbock, TX 79408 | Oil & Gas Operator | Jun 1995 |
| 607 | United Oil & Shale LLC | Woodward, OK 73801 | Oil & Gas Operator | Jun 2026 |
| 608 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 609 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 610 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 611 | Vanguard Permian, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 612 | Vaquero Operating | FT Stockton, TX 79735 | Oil & Gas Operator | Jun 2026 |
| 613 | Venus Exploration, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2013 |
| 614 | Venus Oil Company | San Antonio, TX 78209 | Oil & Gas Operator | Dec 2002 |
| 615 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Jun 2026 |
| 616 | Vision Oil And Gas LLC | Laredo, TX 78041 | Oil & Gas Operator | Jun 2026 |
| 617 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 618 | Vital Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Jun 2026 |
| 619 | Walbet | Monahans, TX 79756 | Oil & Gas Operator | Dec 1993 |
| 620 | Walbet, Inc. | Monahans, TX 79756 | Oil & Gas Operator | Jun 2026 |
| 621 | Walker, Kent | Midland, TX 79704 | Oil & Gas Operator | Jun 2004 |
| 622 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Jun 2026 |
| 623 | Watson Packer Employee Fund | Monahans, TX 79756 | Oil & Gas Operator | Jun 2026 |
| 624 | WCWB Energy, LLC | Midland, TX 79701 | Oil Operator | Sep 2015 |
| 625 | West Bay Exploration Company | Muenster, TX 76252 | Oil & Gas Operator | Mar 2026 |
| 626 | Westar Energy, Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 627 | Western DRLG. Co. | Longview, TX 75604 | Oil & Gas Operator | Nov 1996 |
| 628 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 629 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 630 | Wheeler Operating Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Jun 2026 |
| 631 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2026 |
| 632 | Wilbanks, Bruce A. | Midland, TX 79701 | Oil & Gas Operator | Aug 1996 |
| 633 | Wilco Operating | Monahans, TX 79756 | Oil & Gas Operator | Jun 2026 |
| 634 | Wild Cat Operating Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 635 | Williams Oil Company | Midland, TX 79710 | Oil & Gas Operator | Jun 2026 |
| 636 | Wind River Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Jun 2026 |
| 637 | Wind River Resources Inc | Tulsa, OK 74136-6381 | Oil & Gas Operator | Jun 2010 |
| 638 | Winfield Operating Company | Dallas, TX 75214 | Oil & Gas Operator | Jun 2026 |
| 639 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 640 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Jun 2026 |
| 641 | Wood, McShane & Thams | Midland, TX 79702 | Oil & Gas Operator | Oct 1995 |
| 642 | Wrath Energy, LLC | Odessa, TX 79760 | Oil Operator | Jun 2026 |
| 643 | WTG Exploration | Midland, TX 79705 | Oil & Gas Operator | Jun 2026 |
| 644 | Wyco Oil & Gas LLC | Odessa, TX 79766 | Oil & Gas Operator | Jan 2024 |
| 645 | Wynco Energy, Inc. | Spring, TX 77393 | Oil & Gas Operator | Jun 2026 |
| 646 | Xeric Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 647 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 648 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 649 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Jun 2026 |
| 650 | Yates Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 651 | Younger Energy Company | Wichita, KS 67206 | Oil & Gas Operator | Jun 2026 |
| 652 | Yucca Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2026 |
| 653 | Zachry Oil And Gas Properties | Midland, TX 79708 | Oil & Gas Operator | Jun 2026 |
| 654 | Zarvona Energy LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2026 |