| 501 | Seismotech Energy, Incorporated | Plano, TX 75075 | Oil & Gas Operator | Aug 2003 |
| 502 | Seneca Exploration, LLC | Wichita Falls, TX 76308 | Oil Operator | Feb 2026 |
| 503 | Sep, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1994 |
| 504 | Sevenx, LLC | Iowa Park, TX 76367 | Oil Operator | Feb 2026 |
| 505 | Shappell Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Sep 2012 |
| 506 | Shappell Oil Company, L.L.C. | Harrisonburg, LA 71340 | Oil & Gas Operator | Feb 2026 |
| 507 | Share Petroleum Corp. | Mabank, TX 75147 | Oil Operator | Feb 2026 |
| 508 | Shed Oil Company | Electra, TX 76360 | Oil Operator | Feb 2026 |
| 509 | Shelley, Richard W | Wichita Falls, TX 76310 | Oil & Gas Operator | Jun 2015 |
| 510 | Sherman Oil Company LLC | Wichita Falls, TX 76308 | Oil Operator | Apr 2025 |
| 511 | Sigma Exploration Corp., The | Dallas, TX 75230 | Oil & Gas Operator | Sep 1998 |
| 512 | Simpson, A. E. | Electra, TX 76360 | Oil & Gas Operator | Dec 2006 |
| 513 | Sissom Oil | Holliday, TX 76366 | Oil & Gas Operator | Mar 2008 |
| 514 | Sissom Oil Field Services, LLC | Graham, TX 76450 | Oil Operator | Feb 2026 |
| 515 | Skinner, W. E. | Wichita Falls, TX 76301 | Oil & Gas Operator | Feb 2026 |
| 516 | Skybridge Energy LLC | Jacksboro, TX 76458 | Oil & Gas Operator | Feb 2026 |
| 517 | Slant Operating, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Feb 2026 |
| 518 | Slate Holdings, Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Feb 2026 |
| 519 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 520 | Smith, Ted H. | Wichita Falls, TX 76310 | Oil & Gas Operator | Sep 1998 |
| 521 | Smulcer, Jimmy A. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2002 |
| 522 | Spearco Oil | Electra, TX 76360 | Oil & Gas Operator | Aug 2003 |
| 523 | Special JHR Corp | Bridgeville, PA 15017 | Oil & Gas Operator | Feb 2026 |
| 524 | SPH Development, LLC | Wichita Falls, TX 76308 | Oil & Gas Operator | Nov 2022 |
| 525 | Spitfire Partners, LLC | Dallas, TX 75225 | Oil Operator | Feb 2026 |
| 526 | Spragins, Ed | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 527 | Spruiell Drilling Co., Inc. | Holliday, TX 76366 | Oil & Gas Operator | Feb 2026 |
| 528 | St. Cajetan Oil Company, LLC | Gainesville, TX 76240 | Oil & Gas Operator | Feb 2026 |
| 529 | Stagg Investment Group, Inc. | Midland, TX 79701 | Oil Operator | May 2013 |
| 530 | Staley Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2000 |
| 531 | Staley, Jack C. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2000 |
| 532 | Starr Operating Company | Austin, TX 78759 | Oil & Gas Operator | Feb 2026 |
| 533 | Statia Enterprises, Inc | Irving, TX 75014 | Oil & Gas Operator | Feb 2026 |
| 534 | Steinberger, Gerald | Windthorst, TX 76389 | Oil & Gas Operator | Sep 2007 |
| 535 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 536 | Stone & Williams Oil&Gas Co.,Inc | Holliday, TX 76366 | Oil Operator | Apr 2013 |
| 537 | Stone, B. W. | Holliday, TX 76366 | Oil & Gas Operator | Feb 2012 |
| 538 | Stone, Gregory W. | Holliday, TX 76366 | Oil & Gas Operator | Feb 2026 |
| 539 | Storm Oil | Burkburnett, TX 76354 | Oil & Gas Operator | Feb 2026 |
| 540 | Strange, D. D. | Archer City, TX 76351 | Oil & Gas Operator | Sep 2014 |
| 541 | Strange, Joyce Marital Trust | Holliday, TX 76366 | Oil Operator | May 2008 |
| 542 | Stray Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Aug 2008 |
| 543 | Stray Oil Company, LLC | Burkburnett, TX 76354 | Oil Operator | Nov 2017 |
| 544 | Sunrise Enterprises | Bowie, TX 76230 | Oil & Gas Operator | Dec 2016 |
| 545 | Sunrise Oil, LTD. | Wichita Falls, TX 76307 | Oil & Gas Operator | Aug 2004 |
| 546 | Surge Solutions, Inc. | Bandera, TX 78003 | Oil & Gas Operator | Feb 2026 |
| 547 | Sutterfield-Tisdale-Payne, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Jun 1998 |
| 548 | Swanner Properties | Wichita Falls, TX 76309 | Oil & Gas Operator | Feb 2026 |
| 549 | Swanson & Vestal | Electra, TX 76360 | Oil & Gas Operator | Oct 1997 |
| 550 | Swanson Operating, Inc. | Holliday, TX 76366 | Oil Operator | Feb 2026 |
| 551 | Swanson, Tom | Electra, TX 76360 | Oil & Gas Operator | Oct 2004 |
| 552 | Swanson, Tommy Oil Co. | Electra, TX 76360 | Oil & Gas Operator | Mar 2017 |
| 553 | Swenson Backhoe Service, Inc. | Electra, TX 76360 | Oil Operator | Feb 2026 |
| 554 | SWJN Oil Company | Kilgore, TX 75663 | Oil Operator | Feb 2026 |
| 555 | Syntax Energy Corporation | Denton, TX 76210 | Oil Operator | Feb 2026 |
| 556 | T & D Oil | Wichita Falls, TX 76307 | Oil & Gas Operator | Feb 2026 |
| 557 | T & M Oil Company | Midlothian, TX 76065 | Oil & Gas Operator | Feb 2026 |
| 558 | T. R. Production, Inc. | Pilot Point, TX 76258 | Oil & Gas Operator | Jul 2021 |
| 559 | T.F. Well Service, L.L.C. | Iowa Park, TX 76367 | Oil Operator | Feb 2026 |
| 560 | Talley, Don R. | Holliday, TX 76366 | Oil & Gas Operator | Jun 2002 |
| 561 | Talon Production, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Feb 2026 |
| 562 | Talus Inc | Graham, TX 76450-1210 | Oil & Gas Operator | Feb 2017 |
| 563 | Tara Company, The | Wichita Falls, TX 76301 | Oil Operator | Sep 2003 |
| 564 | Taylor Properties | Wichita Falls, TX 76301 | Gas Operator | Feb 2026 |
| 565 | Tember Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Feb 2026 |
| 566 | Texaco E & P Inc. | Houston, TX 77099 | Oil & Gas Operator | Feb 2026 |
| 567 | Texaco Exploration & Prod | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 568 | Texas Energy Operations, LC | Wichita Falls, TX 76301 | Oil & Gas Operator | Feb 2026 |
| 569 | Texas Green Energy Services LLC | Richmond, TX 77407 | Oil Operator | Feb 2026 |
| 570 | Texoma Oil Tools, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Feb 2026 |
| 571 | Thomas Production | Electra, TX 76360 | Oil & Gas Operator | Mar 2015 |
| 572 | Tillman, Jack Equipment Co. | Holliday, TX 76366 | Oil & Gas Operator | Sep 2004 |
| 573 | Tracer Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2026 |
| 574 | Tri Star Operating, Inc. | Arlington, TX 76012 | Oil & Gas Operator | Jan 2002 |
| 575 | Trio Operating Company, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2006 |
| 576 | Triple "S" Gas, Inc. | Louisville, KY 40255 | Oil & Gas Operator | Jan 2026 |
| 577 | Triton Operating LLC | Wichita Falls, TX 76310 | Oil & Gas Operator | Feb 2026 |
| 578 | True Wolf Operating, LLC | Iowa Park, TX 76367 | Oil Operator | Feb 2026 |
| 579 | TS & T Drilling, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2016 |
| 580 | Tucker Resources, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2003 |
| 581 | Turnbow Drilling Co. | Holliday, TX 76366 | Oil & Gas Operator | Jul 2025 |
| 582 | Tuthill & Barbee | Amarillo, TX 79101 | Oil & Gas Operator | Nov 1994 |
| 583 | Twilight Energy LLC | Fort Worth, TX 76185 | Oil & Gas Operator | Feb 2026 |
| 584 | Txon Partners, LLC | Houston, TX 77057 | Oil & Gas Operator | Jun 2017 |
| 585 | Txu Gas Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2004 |
| 586 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 587 | Uphill Consulting LLC | Pearland, TX 77584 | Oil & Gas Operator | Feb 2026 |
| 588 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Feb 2026 |
| 589 | V S Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Feb 2026 |
| 590 | Vanek, R. J. | Iowa Park, TX 76367 | Oil & Gas Operator | Feb 2026 |
| 591 | Veneto Exploration, LLC | Richardson, TX 75083 | Oil & Gas Operator | Feb 2026 |
| 592 | Vestal, L. D. Oil Company | Fort Worth, TX 76132 | Oil & Gas Operator | Feb 2026 |
| 593 | Vestal, W. D., Oil Co. | Iowa Park, TX 76367 | Oil & Gas Operator | Dec 1998 |
| 594 | Victory Oil & Gas Inc | Gun Barrel Cy, TX 75156 | Oil & Gas Operator | Feb 2026 |
| 595 | Vinland Texas Services LLC | Electra, TX 76360 | Oil & Gas Operator | Jun 2024 |
| 596 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Feb 2026 |
| 597 | W & W Production, LLC | Wichita Falls, TX 76308 | Oil Operator | Feb 2026 |
| 598 | W T X Capital Investments, LLC | Wichita Falls, TX 76308 | Oil Operator | Feb 2026 |
| 599 | W.T. Waggoner Estate, Inc. | Vernon, TX 76385 | Oil Operator | Feb 2026 |
| 600 | Waggoner Operating, L.L.C. | Vernon, TX 76385 | Oil Operator | Feb 2026 |