| 401 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 402 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 403 | Stanolind Operating Corp. | Midland, TX 79701 | Oil & Gas Operator | Apr 2008 |
| 404 | Stanolind Production LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2020 |
| 405 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Jul 2025 |
| 406 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 407 | Stephenson Oil & Gas, Inc. | Eastland, TX 76448 | Oil & Gas Operator | Sep 1999 |
| 408 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Jul 2025 |
| 409 | Sunergon Oil Operating, LLC | Gainesville, TX 76240 | Oil Operator | Jul 2025 |
| 410 | Swepi LP | Houston, TX 77079 | Oil & Gas Operator | Jul 2020 |
| 411 | Synergy Oil & Gas, Inc. (A) | Houston, TX 77024 | Oil & Gas Operator | Aug 2001 |
| 412 | Synergy Production Company | Houston, TX 77024 | Oil & Gas Operator | Jan 1996 |
| 413 | T-N-T Engineering, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Jul 2025 |
| 414 | T.G.B., Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 415 | Tag Operating Company, Inc. | Houston, TX 77092 | Oil & Gas Operator | Jul 2025 |
| 416 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 417 | Tap Rock Operating, LLC | Denver, CO 80203 | Oil & Gas Operator | Jul 2025 |
| 418 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 419 | Taurus Exploration U.S.A., Inc. | Midland, TX 79705 | Oil & Gas Operator | Nov 1998 |
| 420 | Teke Production LLC | Houston, TX 77269 | Oil Operator | Jul 2025 |
| 421 | Tema Oil And Gas Company | Houston, TX 77084 | Oil & Gas Operator | Jul 2025 |
| 422 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | Jul 2025 |
| 423 | Texas Consolidated Pet. Corp. | Fort Worth, TX 76109 | Oil & Gas Operator | Jul 2025 |
| 424 | Texas Mineral Group | Midland, TX 79705 | Oil & Gas Operator | Aug 2013 |
| 425 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 426 | Three-B Oil Company, The | Monahans, TX 79756 | Oil & Gas Operator | Jul 2025 |
| 427 | Thunderbolt Petroleum Co. LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2011 |
| 428 | Titan Resources I, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2000 |
| 429 | Titus Oil & Gas Production, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2022 |
| 430 | Tiza Energy, Inc. | Austin, TX 78715 | Oil & Gas Operator | Jul 2025 |
| 431 | TMBR/Sharp Drilling, Inc. | Midland, TX 79703 | Oil & Gas Operator | Feb 2004 |
| 432 | Tola Production Company | Dallas, TX 75367 | Oil & Gas Operator | Jul 2025 |
| 433 | Tom E. Johnson Exploration LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2019 |
| 434 | Trail Mountain, Inc. | Artesia, NM 88210 | Oil & Gas Operator | Jan 2016 |
| 435 | Triple "N" Services, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 436 | TRP Operating LLC | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 437 | U S Energy Corp. Of Amer. Inc. | Ranger, TX 76470 | Oil & Gas Operator | Jul 2025 |
| 438 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 439 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Sep 2002 |
| 440 | Union Royalty, Inc. | Midland, TX 79706 | Oil & Gas Operator | Jul 2014 |
| 441 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Jul 2025 |
| 442 | Valley Gathering Company | Midland, TX 79702 | Oil & Gas Operator | Feb 1997 |
| 443 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2021 |
| 444 | Vaquero Gas Company,Incorporated | Houston, TX 77002 | Oil & Gas Operator | Jun 1993 |
| 445 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Jul 2025 |
| 446 | Vital Energy, Inc. | Tulsa, OK 74120 | Oil & Gas Operator | Jul 2025 |
| 447 | Wadi Petroleum Inc | Houston, TX 77014 | Oil & Gas Operator | May 2018 |
| 448 | Wagner Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 449 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Jul 2025 |
| 450 | Warren, Earl T. | San Angelo, TX 76906 | Oil & Gas Operator | Jul 2025 |
| 451 | Waterbridge Texas Operating LLC | Houston, TX 77056 | Oil & Gas Operator | Jul 2025 |
| 452 | Watusi Energy LLC | Midland, TX 79710 | Oil & Gas Operator | Jul 2025 |
| 453 | Waylander LLC | Plano, TX 75025 | Oil & Gas Operator | Jul 2025 |
| 454 | Western Global Oil, Inc | Deerfld Beach, FL 33442 | Oil Operator | Jul 2025 |
| 455 | Western Oil Company | Midland, TX 79702 | Oil & Gas Operator | Jul 2014 |
| 456 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 457 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 458 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 459 | Wheeler Energy Co. | Tulsa, OK 74101 | Oil & Gas Operator | Apr 2025 |
| 460 | Wheeler Energy, LLC | Tulsa, OK 74101 | Oil & Gas Operator | Jul 2025 |
| 461 | Whiting Oil And Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 462 | Wilco Properties, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jan 2004 |
| 463 | Wild Cat Operating Company | Victoria, TX 77903 | Oil & Gas Operator | Mar 2008 |
| 464 | Williams, Clayton Energy, Inc. | Houston, TX 77070 | Oil & Gas Operator | Jul 2025 |
| 465 | Williams, Clayton Energy, L.L.C | Midland, TX 79705 | Oil & Gas Operator | May 1993 |
| 466 | Williams, Clayton W., Jr., Inc. | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 467 | Williamson, J. C. | Midland, TX 79701 | Oil & Gas Operator | Jan 2001 |
| 468 | Williamson, Ralph E. | Midland, TX 79702 | Oil & Gas Operator | Jan 2012 |
| 469 | Wiser Oil Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2023 |
| 470 | Wolf Energy | Midland, TX 79701 | Oil & Gas Operator | Jan 1995 |
| 471 | Wolf Energy, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2021 |
| 472 | WPX Energy Permian, LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 2025 |
| 473 | Xeric Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 474 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 475 | Xog Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 476 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 477 | Yates Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |