| 401 | Shoshone Oil Company | Dallas, TX 75244 | Oil & Gas Operator | May 1994 |
| 402 | Sinclair Oil & Gas Company | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Feb 2026 |
| 403 | Sinclair Oil Corporation | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Aug 2006 |
| 404 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 405 | Sogc, Inc. | Salt Lake Cty, UT 84131 | Oil & Gas Operator | Dec 2025 |
| 406 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 407 | Sounion Petroleum Incorporated | Baltimore, MD 21218 | Oil & Gas Operator | Aug 1994 |
| 408 | Southern Alliance Oil Corp. | Grapevine, TX 76099 | Oil & Gas Operator | Feb 2026 |
| 409 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 410 | Southlake Exploration, Inc. | Southlake, TX 76092 | Oil & Gas Operator | Feb 2026 |
| 411 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 412 | Spalding Energy, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 413 | Spence Energy Company | Dallas, TX 75360 | Oil & Gas Operator | Feb 2026 |
| 414 | Spenergy Corp. | Midland, TX 79701 | Oil & Gas Operator | Dec 1999 |
| 415 | SRG Oil Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 1994 |
| 416 | St. Clair Energy Corporation | Tulsa, OK 74153 | Oil & Gas Operator | Mar 2008 |
| 417 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Feb 2026 |
| 418 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 419 | Stearns Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Oct 1993 |
| 420 | Stephens Exploration, Inc. | Dallas, TX 75367 | Oil & Gas Operator | Dec 2025 |
| 421 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 422 | Sundial Resources, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 423 | Sunstone Energy Company | Tulsa, OK 74153 | Oil & Gas Operator | Aug 2009 |
| 424 | Susanna Corporation | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 425 | Sutton Oil Co. | San Antonio, TX 78254 | Oil & Gas Operator | Feb 2026 |
| 426 | Sweetwater Drilling Co., Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Feb 2026 |
| 427 | Sweetwater Production, Inc. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2026 |
| 428 | T.O.I. | Midland, TX 79710 | Oil & Gas Operator | Mar 2001 |
| 429 | Tahoe Exploration Inc. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2016 |
| 430 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Feb 2026 |
| 431 | Tanglewood Production | Breckenridge, TX 76424 | Oil & Gas Operator | May 2009 |
| 432 | Taurus Operating, Inc. | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 433 | TC Energy LLC | Covington, OK 73730-2116 | Oil & Gas Operator | Sep 2014 |
| 434 | TCS Petroleum Co., LLC | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 435 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 436 | Teague Operating Co. | Mabank, TX 75147 | Oil & Gas Operator | Jul 1995 |
| 437 | Terrace Petroleum Corporation | Midland, TX 79701 | Oil & Gas Operator | Jul 2013 |
| 438 | Terrell Oil & Gas Production Co. | Hamlin, TX 79520 | Oil & Gas Operator | Feb 2026 |
| 439 | Tex-Ann Oil & Gas Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Feb 2026 |
| 440 | Tex-Atic Resources, Inc. | S. Lake Tahoe, CA 96150 | Oil & Gas Operator | Feb 2026 |
| 441 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Feb 2026 |
| 442 | Texas Pharchem Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2019 |
| 443 | Texical, Inc. | Katy, TX 77491 | Oil & Gas Operator | Feb 2026 |
| 444 | Texoma Oil Tools, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 445 | Texstar North America, Inc. | Waynesboro, MS 39367 | Oil & Gas Operator | Aug 1994 |
| 446 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Feb 2026 |
| 447 | Texzona Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1997 |
| 448 | Thompson, Richard W. Inc. | Plano, TX 75024 | Oil & Gas Operator | Feb 2026 |
| 449 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 450 | Tiburon Oil & Gas, Inc. | Midland, TX 79701 | Oil & Gas Operator | Aug 2000 |
| 451 | Titan Energy, Inc. | Austin, TX 78703 | Oil & Gas Operator | Feb 2026 |
| 452 | Townsend Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2021 |
| 453 | Tuthill & Barbee | Amarillo, TX 79101 | Oil & Gas Operator | Nov 1994 |
| 454 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 455 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 456 | United States Gypsum Company | Oakfield, NY 14125 | Oil & Gas Operator | Dec 2024 |
| 457 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Feb 2026 |
| 458 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 459 | Van Operating, LTD. | Albany, TX 76430 | Oil & Gas Operator | Feb 2026 |
| 460 | Veneto Exploration, LLC | Richardson, TX 75083 | Oil & Gas Operator | Feb 2026 |
| 461 | Vertox LLC | Southlake, TX 76092 | Oil Operator | May 2025 |
| 462 | Viathon Hydrocarbons, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Oct 2020 |
| 463 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 464 | VX Operating, LLC | Abilene, TX 79605 | Oil & Gas Operator | Feb 2026 |
| 465 | W.H.D., Inc. | Euless, TX 76039 | Oil & Gas Operator | Aug 1998 |
| 466 | Walbet, Inc. | Monahans, TX 79756 | Oil & Gas Operator | Feb 2026 |
| 467 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Feb 2026 |
| 468 | Walsh Resources, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Feb 2026 |
| 469 | Walter Exploration Company | Dallas, TX 75206 | Oil & Gas Operator | Feb 2026 |
| 470 | Walter Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | May 2009 |
| 471 | Walter Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 472 | Walton Producing Company | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2005 |
| 473 | Walton Producing Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Feb 2026 |
| 474 | Weakland Investments, Inc. | Denver, CO 80215 | Oil & Gas Operator | Feb 2026 |
| 475 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 476 | Westico Energy Co. | Abilene, TX 79605 | Oil & Gas Operator | Nov 2004 |
| 477 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 478 | Westwood Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | May 2013 |
| 479 | White Wing Petroleum | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 480 | White Wing Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2012 |
| 481 | White, Frank | Abilene, TX 79604 | Oil & Gas Operator | Feb 2026 |
| 482 | Wilbanks, Bruce A. Company | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 483 | Winchester Energy Operating Co. | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 484 | Winn Operating, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Feb 2026 |
| 485 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Feb 2026 |
| 486 | WTG Exploration | Midland, TX 79705 | Oil & Gas Operator | Feb 2026 |
| 487 | WVH Operating LLC | Aledo, TX 76008 | Oil Operator | Feb 2026 |
| 488 | Xeric Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jul 1997 |
| 489 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 490 | Young Marshall R Oil Co | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 491 | Young, Clint Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 492 | Zachry Oil And Gas Properties | Midland, TX 79708 | Oil & Gas Operator | Feb 2026 |
| 493 | Zzron Inc. | Midland, TX 79704 | Oil & Gas Operator | Aug 2003 |