| 301 | Sinclair Exploration Company | Abilene, TX 79604 | Oil & Gas Operator | Nov 1998 |
| 302 | Sinclair Oil Corporation | Salt Lake Cty, UT 84130 | Oil & Gas Operator | Aug 2006 |
| 303 | Sixess Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 304 | SMC Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 305 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | Dec 2025 |
| 306 | Sojourner Drilling Corporation | Abilene, TX 79604 | Oil & Gas Operator | Dec 2025 |
| 307 | Southern Mineral Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2001 |
| 308 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 309 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 310 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Dec 2025 |
| 311 | Spence Energy Company | Dallas, TX 75360 | Oil & Gas Operator | Dec 2025 |
| 312 | Spiller Operating Co., Inc. | Round Rock, TX 78665 | Oil & Gas Operator | May 2015 |
| 313 | Sproul, C. R. Inc. | Eldorado, TX 76936 | Oil & Gas Operator | Aug 2000 |
| 314 | SRG Oil Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 1994 |
| 315 | SS Operating LLC | Water Valley, TX 76958 | Oil Operator | Dec 2025 |
| 316 | St Johns Operating #1 LP | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 317 | St. Mary Energy Company | Houston, TX 77079 | Oil & Gas Operator | Aug 2008 |
| 318 | Star Production, Inc. | Dallas, TX 75360 | Oil & Gas Operator | Dec 2025 |
| 319 | Startex Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Dec 2025 |
| 320 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 321 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 322 | Sunburst, Inc. | Wheat Ridge, CO 80033 | Oil & Gas Operator | Oct 2025 |
| 323 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | Dec 2025 |
| 324 | Swartz, Guy A. | San Angelo, TX 76904 | Oil & Gas Operator | Aug 1993 |
| 325 | Sweetwater Drilling Co., Inc. | Fort Worth, TX 76116 | Oil & Gas Operator | Dec 2025 |
| 326 | T2 Operating Corporation | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 327 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 328 | Taurus Operating, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 329 | TCS Petroleum Co., LLC | Abilene, TX 79608 | Oil & Gas Operator | Dec 2025 |
| 330 | TDC Engineering, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Dec 2025 |
| 331 | Tenison Oil Company | Abilene, TX 79605 | Oil & Gas Operator | Aug 2025 |
| 332 | Thompson, Richard W. Inc. | Plano, TX 75024 | Oil & Gas Operator | Dec 2025 |
| 333 | Thorp Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2014 |
| 334 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 335 | Tiki Oil & Gas, LLC | Cisco, TX 76437 | Oil Operator | Dec 2025 |
| 336 | Tipperary Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2014 |
| 337 | Townsend Company | Abilene, TX 79608 | Oil & Gas Operator | Dec 2021 |
| 338 | Tracer Energy, Inc. | Graham, TX 76450 | Oil & Gas Operator | Nov 1998 |
| 339 | Triad Energy Corporation | Houston, TX 77057 | Oil & Gas Operator | Oct 2011 |
| 340 | Triangle P Development Corp. | Bronte, TX 76933 | Oil & Gas Operator | Dec 2025 |
| 341 | Tucker Drilling Company, Inc. | San Angelo, TX 76903 | Oil & Gas Operator | Jul 1996 |
| 342 | Turner, D. Ann Garrett, Est. Of | Big Spring, TX 79721 | Oil & Gas Operator | Jan 1999 |
| 343 | Tuthill & Barbee | Amarillo, TX 79101 | Oil & Gas Operator | Nov 1994 |
| 344 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2025 |
| 345 | United Operating, LLC *** | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 346 | Upham, Chester R., Jr. | Mineral Wells, TX 76067 | Oil & Gas Operator | Aug 2001 |
| 347 | Vanco Oil & Gas Corp. | Abilene, TX 79604 | Oil & Gas Operator | Dec 2025 |
| 348 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Aug 2019 |
| 349 | Vanguard Permian, LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 350 | Verado Energy, Inc. | Allen, TX 75013 | Oil & Gas Operator | Oct 2025 |
| 351 | Viola Production Inc | Dallas, TX 75251 | Oil & Gas Operator | Dec 2025 |
| 352 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 353 | Voil Petroleum | Olney, TX 76374 | Oil & Gas Operator | Aug 2004 |
| 354 | W.W. Energy | Luling, TX 78648 | Oil & Gas Operator | Dec 2025 |
| 355 | Wagman Petroleum, Inc. | Dallas, TX 75202 | Oil & Gas Operator | Dec 2025 |
| 356 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | Dec 2025 |
| 357 | Walsh Resources, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Dec 2025 |
| 358 | Wapiti Operating, LLC | Houston, TX 77043 | Oil & Gas Operator | Dec 2025 |
| 359 | Warren American Oil Co | Tulsa, OK 74147 | Oil & Gas Operator | Oct 2025 |
| 360 | Watco Energy, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Apr 1996 |
| 361 | Wes-Tex Drilling Company | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 362 | Western Reserves Oil Co Inc | Midland, TX 79705 | Oil & Gas Operator | Oct 2020 |
| 363 | Westoil LLC | Austin, TX 78747 | Oil & Gas Operator | Dec 2025 |
| 364 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 365 | Wilson, WM. B. Exploration Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 1996 |
| 366 | Wishbone Texas Operating Co LLC | Houston, TX 77064 | Oil & Gas Operator | Jul 2019 |
| 367 | WJC, Inc. | Post, TX 79356 | Oil & Gas Operator | Dec 2025 |
| 368 | Wolcott, Ed Operating | Dallas, TX 75205 | Oil & Gas Operator | Oct 2000 |
| 369 | Wolfson, I. J. | Wichita Falls, TX 76301 | Oil & Gas Operator | Apr 2002 |
| 370 | Xplore Operating, LLC | Arlington, TX 76001 | Oil & Gas Operator | Dec 2025 |
| 371 | Zachry Oil And Gas Properties | Midland, TX 79708 | Oil & Gas Operator | Dec 2025 |
| 372 | Zebra Oil And Gas | Lubbock, TX 79423 | Oil & Gas Operator | Aug 2002 |