| 601 | Spartan Oil Corporation | Abilene, TX 79601 | Oil & Gas Operator | Aug 2003 |
| 602 | Spence Energy Company | Dallas, TX 75360 | Oil & Gas Operator | May 2025 |
| 603 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | May 2025 |
| 604 | Spirit Energy L.L.C. | Caddo Mills, TX 75135 | Oil & Gas Operator | Dec 2018 |
| 605 | Spruiell Drilling Co., Inc. | Holliday, TX 76366 | Oil & Gas Operator | May 2025 |
| 606 | SRG Oil Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 1994 |
| 607 | Staley Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2000 |
| 608 | Staley, Jack C. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jan 2000 |
| 609 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | May 2025 |
| 610 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 611 | Stasney, H. R. & Sons, LTD. | Albany, TX 76430 | Oil & Gas Operator | May 2025 |
| 612 | Stearns Operating Company | Abilene, TX 79604 | Oil & Gas Operator | Oct 1993 |
| 613 | Stelzer, J. C. | Post, TX 79356 | Oil & Gas Operator | Dec 1995 |
| 614 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 615 | Stober Oil And Gas Services, LLC | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 616 | Stone & Williams Oil&Gas Co.,Inc | Holliday, TX 76366 | Oil Operator | Apr 2013 |
| 617 | Stovall Operating Co. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 618 | Strand, Carlton Oil | Stamford, TX 79553 | Oil & Gas Operator | May 1997 |
| 619 | Strange, D. D. | Archer City, TX 76351 | Oil & Gas Operator | Sep 2014 |
| 620 | Strawn Operating Co., L.L.C. | El Paso, TX 79912 | Oil Operator | May 2025 |
| 621 | Strawn Partners Operating, LLC | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 622 | Stroube Energy Corporation | Dallas, TX 75248 | Oil & Gas Operator | Jan 2012 |
| 623 | Subsurface Energy Corp. | Coleman, TX 76834 | Oil & Gas Operator | May 2025 |
| 624 | Subsurface Production, Inc. | Coleman, TX 76834 | Oil & Gas Operator | May 2025 |
| 625 | Sulphur River Exploration, Inc. | Dallas, TX 75244 | Oil & Gas Operator | May 2025 |
| 626 | Sundance Consulting Corp. | Abilene, TX 79605 | Oil & Gas Operator | May 2025 |
| 627 | Sundance Resources, Inc. | Rio VIsta, TX 76093 | Oil & Gas Operator | Mar 2012 |
| 628 | Sunwest Oklahoma, Inc | Dallas, TX 75231 | Oil & Gas Operator | May 2023 |
| 629 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | May 2025 |
| 630 | Susanna Corporation | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 631 | Sutton Oil Co. | Austin, TX 78728 | Oil & Gas Operator | May 2025 |
| 632 | Swartz Oil Company | San Angelo, TX 76906 | Oil & Gas Operator | May 2025 |
| 633 | Sweetwater Drilling Co., Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | May 2025 |
| 634 | T & G Energy LLC | Dallas, TX 75230 | Oil Operator | Nov 2010 |
| 635 | T-N-T Engineering, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | May 2025 |
| 636 | T. W. Drilling Co. | Abilene, TX 79601 | Oil & Gas Operator | Aug 2002 |
| 637 | T.L.S. Oil Co. | Hawley, TX 79525 | Oil & Gas Operator | May 2025 |
| 638 | Tabco Exploration Inc. | New Orleans, LA 70131 | Oil & Gas Operator | Dec 1998 |
| 639 | Tahoe Exploration Inc. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2016 |
| 640 | Tankersley, D. C. | Abilene, TX 79601 | Oil & Gas Operator | Sep 2002 |
| 641 | Targo Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 642 | Taylor, J. S. Inc. | Lewisville, TX 75057 | Oil & Gas Operator | May 2025 |
| 643 | TCS Petroleum Co., LLC | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 644 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | May 2025 |
| 645 | Teal Exploration, LLC | Abilene, TX 79602 | Oil Operator | May 2025 |
| 646 | Telesis Operating Co. | Fort Worth, TX 76116 | Oil & Gas Operator | May 2025 |
| 647 | Tetragon Investments, LLC | Abilene, TX 79604 | Oil Operator | Jul 2014 |
| 648 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 649 | Texakoma Oil & Gas Corp | Dallas, TX 75240 | Oil & Gas Operator | Sep 2014 |
| 650 | Texakoma Operating, L.P. | Plano, TX 75024 | Oil & Gas Operator | Jan 2025 |
| 651 | Texas Pharchem Inc. | Abilene, TX 79601 | Oil & Gas Operator | Apr 2019 |
| 652 | Texas United Geoproduction, Inc. | Abilene, TX 79606 | Oil & Gas Operator | May 2025 |
| 653 | Texxol Operating Company, Inc. | Fort Worth, TX 76108 | Oil & Gas Operator | May 2025 |
| 654 | Texzona Oil & Gas, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 1997 |
| 655 | Thompson, Richard W. Inc. | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 656 | Thornton Oil Co. | Abilene, TX 79603 | Oil & Gas Operator | Aug 2003 |
| 657 | Thornton, Michael D. | Breckenridge, TX 76424 | Oil & Gas Operator | Nov 1995 |
| 658 | Throckmorton Oil, Inc. | Throckmorton, TX 76483 | Oil & Gas Operator | Mar 2008 |
| 659 | THT Covenant Holdings, LLC | Wichita Falls, TX 76307 | Oil Operator | May 2025 |
| 660 | Thunderbolt Oil & Gas, Inc. | Abilene, TX 79605 | Oil & Gas Operator | Feb 2004 |
| 661 | Tiara Resources, Inc. | Fort Worth, TX 76179 | Oil & Gas Operator | Apr 1998 |
| 662 | Titan Energy, Inc. | Austin, TX 78703 | Oil & Gas Operator | May 2025 |
| 663 | TKP Petroleum, Inc. | Lubbock, TX 79464 | Oil & Gas Operator | May 2025 |
| 664 | TNT Oil Co. | Hamlin, TX 79520 | Oil & Gas Operator | May 2025 |
| 665 | Tollett Oil | Graham, TX 76450 | Oil Operator | May 2025 |
| 666 | Townes, Don | Clarksville, TX 75426 | Oil & Gas Operator | May 2025 |
| 667 | Townsend Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2021 |
| 668 | Tracer Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Nov 1998 |
| 669 | Tracer Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 670 | Tracker Mineral | Clyde, TX 79510 | Oil & Gas Operator | May 2025 |
| 671 | Trek Resources, Inc. | Dallas, TX 75207 | Oil & Gas Operator | May 2025 |
| 672 | Trey Exploration, Inc. | San Angelo, TX 76901 | Oil & Gas Operator | Dec 2020 |
| 673 | Tri-Force Operating, L.L.C. | Royse City, TX 75189 | Oil & Gas Operator | May 2025 |
| 674 | Tri-Tex Exploration LTD | Abilene, TX 79608 | Oil Operator | Apr 2019 |
| 675 | Tristar Exploration, Inc | Pflugerville, TX 78660 | Oil & Gas Operator | May 2025 |
| 676 | Trust Oil Co. | Pine, CO 80470 | Oil & Gas Operator | May 2025 |
| 677 | TSW Oil & Gas, LLC | Abilene, TX 79602 | Oil & Gas Operator | Jan 2016 |
| 678 | Txu Lone Star Pipeline | Dallas, TX 75201 | Oil & Gas Operator | Oct 2003 |
| 679 | U.S. Energy Development Corp | Fort Worth, TX 76164 | Oil & Gas Operator | May 2025 |
| 680 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | May 2025 |
| 681 | United Energy Partners, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 682 | Upstream Properties, LLC | Southlake, TX 76092 | Oil & Gas Operator | May 2025 |
| 683 | Us. Fuels, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 684 | Valera Oil Company | Kingsland, TX 78639 | Oil & Gas Operator | Apr 2000 |
| 685 | Valley Petroleum Company | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 686 | Valley Resources, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Aug 2003 |
| 687 | Van Operating, LTD. | Albany, TX 76430 | Oil & Gas Operator | May 2025 |
| 688 | Vanco Oil & Gas Corp. | Abilene, TX 79604 | Oil & Gas Operator | May 2025 |
| 689 | Veneto Exploration, LLC | Richardson, TX 75083 | Oil & Gas Operator | May 2025 |
| 690 | Ventex Operating Corp. | Addison, TX 75001 | Oil & Gas Operator | May 2025 |
| 691 | Viathon Hydrocarbons, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Oct 2020 |
| 692 | Victory Oil & Gas Inc | Gun Barrel Cy, TX 75156 | Oil & Gas Operator | May 2025 |
| 693 | Vin Fisher Operating, Inc. | Andrews, TX 79714 | Oil & Gas Operator | May 2025 |
| 694 | Vista Exploration, LLC | Abilene, TX 79601 | Oil & Gas Operator | May 2017 |
| 695 | W.I. Royalty, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Nov 2009 |
| 696 | Wagman, Brent A. | Dallas, TX 75202 | Oil & Gas Operator | May 2025 |
| 697 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | May 2025 |
| 698 | Walter Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | May 2009 |
| 699 | Walton Producing Company | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2005 |
| 700 | Walton Producing Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |