| 501 | Sky Development Corporation | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 502 | Sky Resources, Inc. | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 503 | Skybridge Energy LLC | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2024 |
| 504 | Slate Holdings, Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Dec 2024 |
| 505 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Dec 2024 |
| 506 | Snow Operating Co., Inc. | Haltom City, TX 76117 | Oil & Gas Operator | Feb 2024 |
| 507 | Spartagus Corporation | Grand Saline, TX 75140 | Oil & Gas Operator | Sep 2004 |
| 508 | Spence Energy Company | Dallas, TX 75206 | Oil & Gas Operator | Dec 2024 |
| 509 | Spi Operations LLC | Midland, TX 79710 | Oil & Gas Operator | Jan 2013 |
| 510 | Spindletop Drilling Co. | Dallas, TX 75230 | Oil & Gas Operator | Dec 2024 |
| 511 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | Dec 2024 |
| 512 | SRG Oil Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 1994 |
| 513 | St. Johns Operating #1 L.P. | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 514 | Staley Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2000 |
| 515 | Stamper Operating Co., Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2024 |
| 516 | STB Energy Inc. | Tulsa, OK 74105 | Oil & Gas Operator | Jul 2008 |
| 517 | Steller Energy & Investment Corp | Plano, TX 75093 | Oil & Gas Operator | Feb 2021 |
| 518 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2024 |
| 519 | Stephens Energy Corp. | Graham, TX 76450 | Oil & Gas Operator | Feb 2022 |
| 520 | Stephens, Clayton E. | Dallas, TX 75229 | Oil & Gas Operator | Nov 2011 |
| 521 | Stephens, Hayseed Oil Inc. | Weatherford, TX 76087 | Oil & Gas Operator | Mar 2008 |
| 522 | Stephens, Morris | Graham, TX 76450 | Oil & Gas Operator | May 1996 |
| 523 | Sterling Oil And Gas | Weatherford, TX 76086 | Oil & Gas Operator | Dec 2024 |
| 524 | Stewart & Porter | Mingus, TX 76463 | Oil & Gas Operator | Apr 2002 |
| 525 | Stivers Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 1995 |
| 526 | Stober Oil And Gas Services, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2024 |
| 527 | Stone Creek Operating, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Dec 2024 |
| 528 | Stonebriar Oil LLC | Frisco, TX 75034 | Oil & Gas Operator | Dec 2024 |
| 529 | Stovall Operating Co. | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 530 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 531 | Street, Spencer B., Jr. | Graham, TX 76450 | Oil & Gas Operator | Mar 1998 |
| 532 | Sun-Key Oil Co., Inc. | Dublin, TX 76446 | Oil & Gas Operator | Dec 2024 |
| 533 | Sunrise Oil, LTD. | Wichita Falls, TX 76307 | Oil & Gas Operator | Aug 2004 |
| 534 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Dec 2024 |
| 535 | Swan PC, LP | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2024 |
| 536 | Swan Production Co. | Jacksboro, TX 76458 | Oil & Gas Operator | Nov 2009 |
| 537 | Swartz Oil Company | San Angelo, TX 76906 | Oil & Gas Operator | Dec 2024 |
| 538 | Sweetwater Drilling Co., Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Dec 2024 |
| 539 | Talon Production, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Dec 2024 |
| 540 | Talus Inc | Graham, TX 76450-1210 | Oil & Gas Operator | Feb 2017 |
| 541 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Dec 2024 |
| 542 | Tandem Energy Corporation | Houston, TX 77056 | Oil & Gas Operator | Dec 2024 |
| 543 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 544 | Targo Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 2024 |
| 545 | Tarpon Oil & Gas Co. | Fort Worth, TX 76147 | Oil & Gas Operator | Dec 2024 |
| 546 | Tarpon Oil Company | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2017 |
| 547 | Taubert & Steed | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2001 |
| 548 | Taylor, Ben J. Inc. | Fort Worth, TX 76185 | Oil & Gas Operator | Feb 2022 |
| 549 | Taylor, G. E. | Bridgeport, TX 76426 | Oil & Gas Operator | Jan 2001 |
| 550 | Taylor, J. S. Inc. | Lewisville, TX 75057 | Oil & Gas Operator | Dec 2024 |
| 551 | Tejas Western Corp. | Granbury, TX 76048 | Oil & Gas Operator | Jul 2018 |
| 552 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Dec 2024 |
| 553 | Tempo Resources GP, LLC | Mineral Wells, TX 76068 | Oil & Gas Operator | Apr 2013 |
| 554 | Tessara Petroleum Resources, LLC | Houston, TX 77086 | Oil & Gas Operator | Apr 2020 |
| 555 | Tex-Am Petroleum Corp. | Eastland, TX 76448 | Oil & Gas Operator | Dec 2024 |
| 556 | Texas Pharchem Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2019 |
| 557 | Texas Shallow Oil & Gas, LLC | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 558 | Texdon Operating | Breckenridge, TX 76424 | Oil & Gas Operator | Jun 2005 |
| 559 | Texland-Rector & Schumacher | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2000 |
| 560 | Texu Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Jan 2007 |
| 561 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | Dec 2024 |
| 562 | TFX, Inc. | Graham, TX 76450 | Oil & Gas Operator | Oct 2019 |
| 563 | The Brogdon Company, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2024 |
| 564 | Thomas, R. W. Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 565 | Three B Corporation | Fort Worth, TX 76179 | Gas Operator | Jun 2009 |
| 566 | Three B Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 567 | Three B, LP | Fort Worth, TX 76179 | Gas Operator | Dec 2024 |
| 568 | Three P Operating Co.,GP, L.L.C. | Newcastle, TX 76372 | Oil & Gas Operator | Dec 2024 |
| 569 | Three P Operating Company | Newcastle, TX 76372 | Oil & Gas Operator | Nov 2007 |
| 570 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 571 | Threshold Exploration, Inc. | College Sta, TX 77842 | Oil & Gas Operator | Oct 2015 |
| 572 | Tipperary Oil & Gas Corp | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 573 | Torch Operating LLC | Fort Worth, TX 76135 | Oil & Gas Operator | Oct 2020 |
| 574 | Tower Resources Inc | Conroe, TX 77304 | Oil & Gas Operator | Dec 2024 |
| 575 | Trace Energy Management Inc | Weatherford, TX 76086 | Oil & Gas Operator | Dec 2024 |
| 576 | Tracer Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Nov 1998 |
| 577 | Tracer Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Dec 2024 |
| 578 | Trans Oil Marketing LLC | Abilene, TX 79608 | Oil Operator | Aug 2023 |
| 579 | Trans-Pecos Resources, Inc. | Houston, TX 77056 | Oil & Gas Operator | Dec 2024 |
| 580 | Transcontinental Shale L.L.C. | Austin, TX 78717 | Oil & Gas Operator | Feb 2016 |
| 581 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | Dec 2024 |
| 582 | Tres Azores Oil & Gas, Inc. | Fort Worth, TX 76185 | Oil & Gas Operator | Aug 2003 |
| 583 | Tresami, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2024 |
| 584 | Trey Exploration, Inc. | San Angelo, TX 76901 | Oil & Gas Operator | Dec 2020 |
| 585 | Trey Resources Inc. | Midland, TX 79710 | Oil & Gas Operator | Oct 2024 |
| 586 | Trinity River Energy Oper, LLC | Houston, TX 77008 | Oil & Gas Operator | May 2018 |
| 587 | Trio Consulting & Management,LLC | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2024 |
| 588 | Tripower Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2020 |
| 589 | Tristar Exploration, Inc | Pflugerville, TX 78660 | Oil & Gas Operator | Dec 2024 |
| 590 | Trumter Petroleum Corporation | Fort Worth, TX 76185 | Oil & Gas Operator | Aug 1998 |
| 591 | Trust Oil Co. | Pine, CO 80470 | Oil & Gas Operator | Dec 2024 |
| 592 | United Energy Partners, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 593 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 594 | Upda Operators, Inc. | Jacksboro, TX 76458 | Oil & Gas Operator | Dec 2009 |
| 595 | Upham Oil & Gas Company | Mineral Wells, TX 76068 | Oil & Gas Operator | Dec 2024 |
| 596 | Upham, Chester R., Jr. | Mineral Wells, TX 76067 | Oil & Gas Operator | Aug 2001 |
| 597 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2024 |
| 598 | Vantage Fort Worth Energy LLC | Pittsburgh, PA 15222 | Oil & Gas Operator | Oct 2017 |
| 599 | Veritas Energy LLC | San Antonio, TX 78231 | Oil & Gas Operator | Dec 2024 |
| 600 | Viejo Services, LLC | Boyd, TX 76023 | Oil & Gas Operator | Dec 2024 |