| 501 | Seven Wells Oil & Gas Expl. | Abilene, TX 79601 | Oil & Gas Operator | Jun 2014 |
| 502 | Shack, Bill | Albany, TX 76430 | Oil & Gas Operator | Apr 2006 |
| 503 | Shaida, John H. | Wichita, KS 67226 | Oil & Gas Operator | Apr 2025 |
| 504 | Sheets Exploration Co., Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2016 |
| 505 | Sheets, P. A. | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 1994 |
| 506 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Apr 2025 |
| 507 | Shoshone Oil Company | Dallas, TX 75244 | Oil & Gas Operator | May 1994 |
| 508 | Sierra Exploration Company | San Antonio, TX 78209 | Oil & Gas Operator | Mar 2008 |
| 509 | Simpson Oil & Land Co. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 510 | Slate Holdings, Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Apr 2025 |
| 511 | Smalley, Bill | Albany, TX 76430 | Oil & Gas Operator | Jul 2001 |
| 512 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 513 | Snyder Drilling Corp. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 514 | So Operating Company | Cisco, TX 76437 | Oil & Gas Operator | Apr 2025 |
| 515 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 516 | Southeastern Resources Corp. | Mansfield, TX 76063 | Oil & Gas Operator | Feb 2004 |
| 517 | Southern Exploration, Inc. | Fort Worth, TX 76137 | Oil & Gas Operator | Aug 2023 |
| 518 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 519 | Southwest Gas Systems, Inc. | Spring, TX 77379 | Oil & Gas Operator | Apr 2025 |
| 520 | Spartan Oil Corporation | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 521 | Spring Tree Management LC | Abilene, TX 79604 | Oil Operator | May 2013 |
| 522 | Squyres Oil Co., Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Nov 2024 |
| 523 | Stamper Operating Co., Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Apr 2025 |
| 524 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Apr 2025 |
| 525 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 526 | Stasney Well Service, LLC | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 527 | Stasney, H. R. & Sons, LTD. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 528 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2025 |
| 529 | Stober Oil And Gas Services, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2025 |
| 530 | Stovall Operating Co. | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 531 | Stovall, Troy | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 532 | Strand, Carlton Oil | Stamford, TX 79553 | Oil & Gas Operator | May 1997 |
| 533 | Strawn Operating Co., L.L.C. | El Paso, TX 79912 | Oil Operator | Apr 2025 |
| 534 | Street, Spencer B., Jr. | Graham, TX 76450 | Oil & Gas Operator | Mar 1998 |
| 535 | Strike Too Oil | Albany, TX 76430 | Oil Operator | Apr 2025 |
| 536 | Stryker Energy Corp. | Mesquite, TX 75180 | Oil & Gas Operator | Apr 2025 |
| 537 | Subsea Operating Co. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 538 | Sundance Consulting Corp. | Abilene, TX 79605 | Oil & Gas Operator | Apr 2025 |
| 539 | Sundance Resources, Inc. | Rio VIsta, TX 76093 | Oil & Gas Operator | Mar 2012 |
| 540 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2025 |
| 541 | Sweetwater Drilling Co., Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2025 |
| 542 | Synergy Operating Co., LLC | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 543 | T-N-T Engineering, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Apr 2025 |
| 544 | Tabor Creek Oil Company | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 545 | Talus Inc | Graham, TX 76450-1210 | Oil & Gas Operator | Feb 2017 |
| 546 | Tam2 Squared Energy Services,LLC | Cisco, TX 76437 | Oil Operator | Apr 2025 |
| 547 | Tankersley, D. C. | Abilene, TX 79601 | Oil & Gas Operator | Sep 2002 |
| 548 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 549 | Targo Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 550 | Taylor, Raymond C. Jr. | Woodway, TX 76712 | Oil & Gas Operator | Dec 2012 |
| 551 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2025 |
| 552 | Terry'S Roustabout Service, Inc. | Throckmorton, TX 76483 | Oil & Gas Operator | Oct 2002 |
| 553 | Tetragon Investments, LLC | Abilene, TX 79604 | Oil Operator | Jul 2014 |
| 554 | Tex-Ann Oil & Gas Services, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 555 | Texas Pharchem Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2019 |
| 556 | Texcal Resources, Inc. | Plano, TX 75094 | Oil & Gas Operator | Apr 1994 |
| 557 | Texoma Oil Tools, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2025 |
| 558 | Texowa, LLC | Roanoke, TX 76262 | Oil Operator | Apr 2025 |
| 559 | Texzona Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1997 |
| 560 | Thornton, Michael D. | Breckenridge, TX 76424 | Oil & Gas Operator | Nov 1995 |
| 561 | Three P Operating Co.,GP, L.L.C. | Newcastle, TX 76372 | Oil & Gas Operator | Apr 2025 |
| 562 | Throckmorton Oil, Inc. | Throckmorton, TX 76483 | Oil & Gas Operator | Mar 2008 |
| 563 | Thunderbolt Oil & Gas, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Feb 2004 |
| 564 | Tiara Resources, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | Apr 1998 |
| 565 | Tidmore, Ann | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 566 | Tiki Oil & Gas, LLC | Cisco, TX 76437 | Oil Operator | Apr 2025 |
| 567 | Tollett Oil | Graham, TX 76450 | Oil Operator | Apr 2025 |
| 568 | Tom-Tom Operating, LLC | Dallas, TX 75209 | Oil Operator | Apr 2025 |
| 569 | Tracker Mineral | Clyde, TX 79510 | Oil & Gas Operator | Apr 2025 |
| 570 | Tracker Resource Dev III, LLC | Englewood, CO 80112 | Oil & Gas Operator | Jul 2021 |
| 571 | Trans Oil Marketing LLC | Abilene, TX 79608 | Oil Operator | Aug 2023 |
| 572 | Treco Oil Company | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 573 | Tres Piedras, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Apr 1999 |
| 574 | Tri Sportsmen Energy, Inc. | Austin, TX 78746 | Oil & Gas Operator | Apr 2025 |
| 575 | Tri-Tex Exploration LTD | Abilene, TX 79608 | Oil Operator | Apr 2019 |
| 576 | Triple Singleton, Inc. | Santa Fe, TX 77510 | Oil & Gas Operator | Dec 2020 |
| 577 | Trumter Petroleum Corporation | Fort Worth, TX 76185 | Oil & Gas Operator | Aug 1998 |
| 578 | TSW Oil & Gas, LLC | Abilene, TX 79602 | Oil & Gas Operator | Jan 2016 |
| 579 | U.S. Sovereign Oil And Gas, Inc. | Dallas, TX 75355 | Oil & Gas Operator | Apr 2025 |
| 580 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2025 |
| 581 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 582 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2025 |
| 583 | Valera Oil Company | Kingsland, TX 78639 | Oil & Gas Operator | Apr 2000 |
| 584 | Valley Petroleum Company | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 585 | Van Oil Co Inc | Fort Worth, TX 76116 | Oil Operator | Dec 1997 |
| 586 | Van Operating, LTD. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 587 | Vin Fisher Operating, Inc. | Andrews, TX 79714 | Oil & Gas Operator | Apr 2025 |
| 588 | W.O.G., Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 589 | Waddell, Kent | Abilene, TX 79606 | Oil & Gas Operator | Nov 2010 |
| 590 | Walkabout Operating, LLC | Lubbock, TX 79424 | Oil & Gas Operator | Apr 2025 |
| 591 | Waller, C.W. Oil Co. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 592 | Waters Petroleum | Albany, TX 76430 | Oil & Gas Operator | Aug 2016 |
| 593 | Weaver Global Operating, LLC | Colleyville, TX 76034 | Oil Operator | Apr 2025 |
| 594 | Wells Oilfield Services, Inc. | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 595 | West-States Energy, Inc. | Rimrock, AZ 86335 | Oil Operator | Apr 2025 |
| 596 | Western Reserves Corporation | Abilene, TX 79608 | Oil & Gas Operator | Jan 2008 |
| 597 | Western Sky Oil & Gas | Abilene, TX 79604 | Oil & Gas Operator | Aug 2003 |
| 598 | Westland Oil Development Corp. | Conroe, TX 77305 | Oil & Gas Operator | Mar 2008 |
| 599 | Westridge Oil & Gas Properties | Mineral Wells, TX 76068 | Oil & Gas Operator | Apr 2025 |
| 600 | Westwood Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | May 2013 |