| 501 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Sep 2026 |
| 502 | SMC Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 503 | Smith & Marrs Inc. | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2021 |
| 504 | Smith Energy Operating Company | Lubbock, TX 79423 | Oil & Gas Operator | Mar 2026 |
| 505 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Sep 2026 |
| 506 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 507 | Socorro Exploration, Inc. | Lubbock, TX 79464 | Oil & Gas Operator | Sep 2026 |
| 508 | Sogo III LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2017 |
| 509 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Sep 2026 |
| 510 | Sonat Exploration Co. - Midland | Houston, TX 77251 | Oil & Gas Operator | Mar 1999 |
| 511 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 512 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 513 | Spi Operations LLC | Midland, TX 79710 | Oil & Gas Operator | Jan 2013 |
| 514 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Sep 2026 |
| 515 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | Sep 2026 |
| 516 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 517 | Stanolind Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2021 |
| 518 | Stanolind Production LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2020 |
| 519 | STB Energy Inc. | Tulsa, OK 74105 | Oil & Gas Operator | Jul 2008 |
| 520 | Steadfast Oil & Gas, LLC | Midland, TX 79707 | Oil & Gas Operator | Oct 2022 |
| 521 | Stelbar Oil Corporation, Inc. | Wichita, KS 67206 | Oil & Gas Operator | May 2026 |
| 522 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 523 | Strand Energy, Inc. (I) | Houston, TX 77002 | Oil & Gas Operator | Sep 1996 |
| 524 | Summit Exploration, L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Mar 2008 |
| 525 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Sep 2026 |
| 526 | Sunray Energy, Inc. | Round Rock, TX 78683 | Oil & Gas Operator | Nov 2018 |
| 527 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Sep 2026 |
| 528 | Surge Operating, LLC | Houston, TX 77041 | Oil & Gas Operator | Sep 2026 |
| 529 | Tacoma Operating LLC | Midland, TX 79707 | Oil & Gas Operator | Sep 2026 |
| 530 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 531 | Tara Operating Co. | Lamesa, TX 79331 | Oil & Gas Operator | Aug 2003 |
| 532 | Taurus Exploration U.S.A., Inc. | Midland, TX 79705 | Oil & Gas Operator | Nov 1998 |
| 533 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | Sep 2026 |
| 534 | TCF Energy, Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 535 | TD Oil & Gas LLC | Duncan, OK 73533-1851 | Oil Operator | Apr 2023 |
| 536 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Sep 2026 |
| 537 | Tejas Operators, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2003 |
| 538 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Sep 2026 |
| 539 | Texas Crude Operator, Inc. | Houston, TX 77098 | Oil & Gas Operator | Aug 2017 |
| 540 | Texland Petroleum Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2003 |
| 541 | Texland Petroleum, L.P. | Fort Worth, TX 76107 | Oil & Gas Operator | Sep 2026 |
| 542 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 543 | Three Forks Resources, LLC | Wheat Ridge, CO 80033 | Oil & Gas Operator | Sep 2026 |
| 544 | Three Rivers Operating Co II LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 545 | Three Span Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 546 | Tipperary Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 547 | TMBR/Sharp Drilling, Inc. | Midland, TX 79703 | Oil & Gas Operator | Feb 2004 |
| 548 | Tola Production Company | Dallas, TX 75367 | Oil & Gas Operator | Sep 2026 |
| 549 | Toreador Exploration & Prod Inc | Dallas, TX 75240 | Oil & Gas Operator | Feb 2008 |
| 550 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Sep 2026 |
| 551 | Trico Energy LLC | Hager Hill, KY 41222 | Oil Operator | Dec 2018 |
| 552 | Trilogy Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | Sep 2026 |
| 553 | Trinity Bay Oil & Gas, Inc. | Lubbock, TX 79416 | Oil & Gas Operator | Sep 2026 |
| 554 | Trinity Operating & Prod., Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 555 | Trio Operating Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2006 |
| 556 | Triple "N" Services, Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 557 | Triple T Resources, LP | Dallas, TX 75205 | Oil & Gas Operator | May 2026 |
| 558 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 559 | U. S. Energy Development Corporation | Fort Worth, TX 76164 | Oil & Gas Operator | Sep 2026 |
| 560 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Jul 2025 |
| 561 | Ultra Oil & Gas, Inc. | Centerton, AR 72719 | Oil & Gas Operator | Sep 2026 |
| 562 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 563 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 564 | Union Royalty, Inc. | Midland, TX 79706 | Oil & Gas Operator | Jul 2014 |
| 565 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Sep 2026 |
| 566 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 567 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 568 | Vaughn Petroleum, Inc. | Dallas, TX 75219 | Oil & Gas Operator | May 2004 |
| 569 | Vision Minerals, LLC | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 570 | Vision Oil And Gas LLC | Laredo, TX 78041 | Oil & Gas Operator | Sep 2026 |
| 571 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 572 | Voskamp Exploration, Inc. | Midland, TX 79708 | Oil & Gas Operator | Sep 2010 |
| 573 | W&T Offshore, Inc. | Houston, TX 77057 | Oil & Gas Operator | Sep 2026 |
| 574 | W. T. Boyle & Co. | Graham, TX 76450 | Oil Operator | Mar 2008 |
| 575 | Walkabout Operating, LLC | Lubbock, TX 79424 | Oil & Gas Operator | Sep 2026 |
| 576 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Sep 2026 |
| 577 | Walsh Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2022 |
| 578 | Walsh, F H Jr. Operating Co. Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2019 |
| 579 | Warren American Oil Co | Tulsa, OK 74147 | Oil & Gas Operator | Jul 2026 |
| 580 | Warrior Exploration LLC | Sapulpa, OK 74067-1912 | Oil & Gas Operator | Mar 2026 |
| 581 | Watusi Energy LLC | Midland, TX 79710 | Oil & Gas Operator | Sep 2026 |
| 582 | Way, Ralph L., Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2026 |
| 583 | Wheeler Operating Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Sep 2026 |
| 584 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Sep 2026 |
| 585 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2026 |
| 586 | Whiting Petroleum Corporation | Denver, CO 80290 | Oil & Gas Operator | Jan 2025 |
| 587 | Wilco Properties, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jan 2004 |
| 588 | Wildcat Energy, LLC | Odessa, TX 79768 | Oil & Gas Operator | Jul 2021 |
| 589 | Willow Creek Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2009 |
| 590 | Wilson, WM. B. Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 1996 |
| 591 | Winfrey Oil Co., Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2016 |
| 592 | Winn Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2026 |
| 593 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 594 | Woodbine Production Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2026 |
| 595 | WTG Exploration | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 596 | WTG Exploration Inc | Midland, TX 79705 | Oil & Gas Operator | Dec 2023 |
| 597 | Wynn-Crosby Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 598 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 599 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Sep 2026 |
| 600 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Sep 2026 |