| 501 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 502 | Stagg Investment Group, Inc. | Midland, TX 79701 | Oil Operator | May 2013 |
| 503 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 504 | Stasney, H. R. & Sons, LTD. | Albany, TX 76430 | Oil & Gas Operator | Aug 2026 |
| 505 | Steller Energy & Investment Corp | Plano, TX 75093 | Oil & Gas Operator | Feb 2021 |
| 506 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 507 | Stratco Operating Co., Inc. | Austin, TX 78701 | Oil & Gas Operator | Aug 2026 |
| 508 | Summit Petroleum LLC | Midland, TX 79705 | Oil & Gas Operator | Aug 2026 |
| 509 | T.G.B., Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2026 |
| 510 | Tacor Resources Inc | Midland, TX 79705 | Oil & Gas Operator | Aug 2026 |
| 511 | Tall Dune Resources, LLC | Houston, TX 77269 | Oil & Gas Operator | Aug 2026 |
| 512 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2026 |
| 513 | Targa Midstream Services LLC | Tulsa, OK 74103 | Oil Operator | Mar 2023 |
| 514 | Targa Pipeline Mid-Continent LLC | Houston, TX 77002 | Oil & Gas Operator | Jun 2018 |
| 515 | Taurus Exploration U.S.A., Inc. | Midland, TX 79705 | Oil & Gas Operator | Nov 1998 |
| 516 | TC Oil And Gas, LLC | Denton, TX 76205 | Oil Operator | Aug 2026 |
| 517 | TD Oil & Gas LLC | Duncan, OK 73533-1851 | Oil Operator | Apr 2023 |
| 518 | Tejas Permian Operating, LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2026 |
| 519 | Tejones Operating Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Aug 2026 |
| 520 | Tempo Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2026 |
| 521 | Terrace Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Jul 2013 |
| 522 | Terrapin Energy LLC | Okmulgee, OK 74447 | Oil Operator | Jun 2026 |
| 523 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Aug 2026 |
| 524 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 525 | Texas Crude Operator, Inc. | Houston, TX 77098 | Oil & Gas Operator | Aug 2017 |
| 526 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 527 | Texas Investments | San Angelo, TX 76904 | Oil & Gas Operator | Mar 2008 |
| 528 | Texon Oil Company, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2023 |
| 529 | Thomas Exploration & Devel., Inc | Jourdanton, TX 78026 | Oil & Gas Operator | Aug 2026 |
| 530 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 531 | Three Rivers Operating Co LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 532 | Titan Resources I, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2000 |
| 533 | TMBR/Sharp Drilling, Inc. | Midland, TX 79703 | Oil & Gas Operator | Feb 2004 |
| 534 | Tom Operating And Minerals LLC | Andrews, TX 79714 | Gas Operator | Aug 2026 |
| 535 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 536 | Townsend Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2021 |
| 537 | Trail Mountain, Inc. | Artesia, NM 88210 | Oil & Gas Operator | Jan 2016 |
| 538 | Trail Ridge Energy PRTNS II LLC | Grapevine, TX 76051 | Oil & Gas Operator | Jun 2017 |
| 539 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Aug 2026 |
| 540 | Trey Resources Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2026 |
| 541 | Trigeo Energy, LLC | Addison, TX 75001 | Oil & Gas Operator | Aug 2026 |
| 542 | Trilogy Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | Aug 2026 |
| 543 | Trinidad Energy, LLC | Midland, TX 79708 | Oil & Gas Operator | Aug 2026 |
| 544 | Trio Production Company, LLC | Stephens, AR 71764 | Oil Operator | Jan 2025 |
| 545 | Triple "N" Services, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2026 |
| 546 | Tripod Oil And Gas 3 LLC | Tulsa, OK 74152 | Oil Operator | Aug 2026 |
| 547 | TSF Operating | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 548 | Turquoise Bay Corporation | Odessa, TX 79760 | Oil & Gas Operator | Dec 2018 |
| 549 | Txu Gas Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2004 |
| 550 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 551 | U. S. Operating, Inc. | Dallas, TX 75252 | Oil & Gas Operator | Jul 2025 |
| 552 | Uhc Petroleum Corporation | Rocksprings, TX 78880 | Oil & Gas Operator | Aug 2026 |
| 553 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 554 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 555 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 556 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 557 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2026 |
| 558 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Jan 2021 |
| 559 | Vanguard Permian, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 560 | Vector Oil & Gas LP | Midland, TX 79701 | Oil & Gas Operator | Sep 2014 |
| 561 | Vencer Energy, LLC | Abilene, TX 79602 | Oil & Gas Operator | Dec 2023 |
| 562 | Veritas Energy LLC | San Antonio, TX 78231 | Oil & Gas Operator | Aug 2026 |
| 563 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Aug 2026 |
| 564 | Vital Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2026 |
| 565 | Vogel, A. J., Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 1994 |
| 566 | W.O.G., Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 567 | Wagner & Brown, LTD. | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 568 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2026 |
| 569 | Walker, Kent | Midland, TX 79704 | Oil & Gas Operator | Jun 2004 |
| 570 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Aug 2026 |
| 571 | Walsh Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2022 |
| 572 | Walter Exploration Company | Dallas, TX 75206 | Oil & Gas Operator | Aug 2026 |
| 573 | Walter Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | May 2009 |
| 574 | Walton Properties LTD. | Midland, TX 79702 | Oil & Gas Operator | Feb 2004 |
| 575 | Watusi Energy LLC | Midland, TX 79710 | Oil & Gas Operator | Aug 2026 |
| 576 | Way, Ralph L., Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2026 |
| 577 | Westar Energy, Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 578 | Western Disposal Systems, Inc. | Corrales, NM 87048 | Oil Operator | Aug 2026 |
| 579 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 580 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Jun 2026 |
| 581 | Whittier Operating Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2007 |
| 582 | Williamson, Ralph E. | Midland, TX 79702 | Oil & Gas Operator | Jan 2012 |
| 583 | Wilson, W. Corp. | Midland, TX 79705 | Oil & Gas Operator | Mar 1999 |
| 584 | Wind River Energy, Inc. | Midland, TX 79710 | Oil & Gas Operator | Aug 2026 |
| 585 | Windsor Energy Group LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2021 |
| 586 | Windsor Permian LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2012 |
| 587 | Wing Corporation | Houston, TX 77002 | Oil & Gas Operator | Jun 2000 |
| 588 | Winn Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2026 |
| 589 | WTG Exploration | Midland, TX 79705 | Oil & Gas Operator | Aug 2026 |
| 590 | WTG Exploration Inc | Midland, TX 79705 | Oil & Gas Operator | Dec 2023 |
| 591 | Wynn-Crosby Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2005 |
| 592 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2026 |
| 593 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Aug 2026 |
| 594 | Yarborough Oil & Gas L.P. | Midland, TX 79701 | Oil & Gas Operator | Oct 2000 |