| 301 | Rife Oil Properties Inc | Fort Worth, TX 76107 | Oil & Gas Operator | May 2025 |
| 302 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | May 2025 |
| 303 | Rio-Tex, Inc. | San Antonio, TX 78217 | Oil & Gas Operator | May 2025 |
| 304 | Robertson Resources, Inc. | Midland, TX 79708 | Oil & Gas Operator | May 2025 |
| 305 | Roc Operating, Inc. | Plano, TX 75093 | Oil & Gas Operator | Oct 2008 |
| 306 | Roca Operating, Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 307 | Roca Resource Company, Inc. | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 308 | Rocker A Operating Company | Post, TX 79356 | Oil & Gas Operator | Aug 2022 |
| 309 | Roemer Oil Company | Denver, CO 80202 | Oil & Gas Operator | Nov 1998 |
| 310 | Rogers, S. K. Oil, Inc. | Lubbock, TX 79424 | Oil & Gas Operator | May 2025 |
| 311 | Rollo Resources, LLC | Granbury, TX 76049 | Gas Operator | May 2025 |
| 312 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 313 | Sabinal Energy Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | May 2025 |
| 314 | Saddle Rim Energy (Texas), LLC | Greenwood VLG, CO 80111 | Oil Operator | May 2025 |
| 315 | Salt Creek Oil Corporation | Irving, TX 75016 | Oil & Gas Operator | Dec 1993 |
| 316 | Salt Creek Production, Inc. | Big Spring, TX 79721 | Oil & Gas Operator | May 2025 |
| 317 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 318 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 319 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 320 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 321 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 322 | Sandridge Tertiary, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2012 |
| 323 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 324 | Scythian, LTD. | Midland, TX 79701 | Oil & Gas Operator | Dec 2020 |
| 325 | Seaboard Oil Company | Midland, TX 79710 | Oil & Gas Operator | Mar 2008 |
| 326 | Seaboard Operating Co. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 327 | Seely Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 328 | Seneca Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Dec 2017 |
| 329 | Shell Land & Energy Co. | Houston, TX 77001 | Oil & Gas Operator | Feb 1997 |
| 330 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 331 | Shenandoah Petroleum Corporation | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 332 | Sierra Lima Oil & Gas, LLC | Abilene, TX 79604 | Oil & Gas Operator | May 2025 |
| 333 | Silver Creek Oil & Gas, LLC | Flower Mound, TX 75022 | Oil & Gas Operator | May 2025 |
| 334 | Silver Spike Energy Oper, LLC | Midland, TX 79710 | Oil & Gas Operator | Dec 2015 |
| 335 | Simmons, L.B. Energy, Inc. | Midland, TX 79705 | Oil & Gas Operator | Nov 2000 |
| 336 | Sink Hole, Inc. | Levelland, TX 79336 | Oil & Gas Operator | Dec 2000 |
| 337 | Sixess Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 338 | Slant Operating, LLC | Lafayette, LA 70503 | Oil & Gas Operator | May 2025 |
| 339 | Slape Oil Company, Inc. | Houston, TX 77064 | Oil & Gas Operator | Jun 2011 |
| 340 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 341 | Socorro Exploration, Inc. | Lubbock, TX 79464 | Oil & Gas Operator | May 2025 |
| 342 | Sogo III LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2017 |
| 343 | Southern Union Exploration Co. | Austin, TX 78701 | Oil & Gas Operator | Feb 2002 |
| 344 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 345 | Southwest Royalties Inc | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 346 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 347 | Springfield Oil Services, Inc. | Mamaroneck, NY 10543 | Oil & Gas Operator | May 2025 |
| 348 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | May 2025 |
| 349 | Stanolind Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2021 |
| 350 | Stanolind Permian LLC | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 351 | Stanolind Production LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2020 |
| 352 | Stoltz, Deane H. | Midland, TX 79710 | Oil & Gas Operator | Oct 2000 |
| 353 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | May 2025 |
| 354 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 355 | T2 Operating Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 356 | Tactical Oil & Gas, LLC | Odessa, TX 79768 | Oil & Gas Operator | May 2025 |
| 357 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 358 | Targa Midstream Services LLC | Houston, TX 77002 | Oil Operator | Mar 2023 |
| 359 | Taubert & Steed | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2001 |
| 360 | Teon Management, LLC | Midland, TX 79704 | Oil & Gas Operator | Mar 2020 |
| 361 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | May 2025 |
| 362 | Texas Crude Operator, Inc. | Houston, TX 77098 | Oil & Gas Operator | Aug 2017 |
| 363 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 364 | Texland Petroleum Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2003 |
| 365 | Texland Petroleum, L.P. | Fort Worth, TX 76107 | Oil & Gas Operator | May 2025 |
| 366 | Texland-Rector & Schumacher | Fort Worth, TX 76102 | Oil & Gas Operator | Nov 2000 |
| 367 | Texlark Exploration Company, Inc | Plano, TX 75074 | Oil & Gas Operator | Sep 2001 |
| 368 | Texon Oil Company, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2023 |
| 369 | Thompson, J. Cleo | Dallas, TX 75201 | Oil & Gas Operator | May 2024 |
| 370 | Three Rivers Operating Co LLC | Austin, TX 78735 | Oil & Gas Operator | Mar 2017 |
| 371 | Three Span Oil & Gas, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 372 | Threshold Development Company | Fort Worth, TX 76109 | Oil & Gas Operator | Aug 2016 |
| 373 | Trail Mountain, Inc. | Artesia, NM 88210 | Oil & Gas Operator | Jan 2016 |
| 374 | Trilogy Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | May 2025 |
| 375 | Trinity Bay Oil & Gas, Inc. | Lubbock, TX 79416 | Oil & Gas Operator | May 2025 |
| 376 | Trinity Eor, LLC | Midland, TX 79701 | Oil & Gas Operator | Jan 2019 |
| 377 | Trousil & Associates, Inc. | Steamboat SPG, CO 80477 | Oil & Gas Operator | Dec 2006 |
| 378 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 379 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 380 | United Company | Lubbock, TX 79408 | Oil & Gas Operator | Jun 1995 |
| 381 | Universal Resources Corp. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jan 2000 |
| 382 | V-F Petroleum Inc. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 383 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | May 2025 |
| 384 | Vanguard Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2021 |
| 385 | Vanguard Permian LLC | Houston, TX 77057 | Oil & Gas Operator | Nov 2018 |
| 386 | Verdad Oil & Gas Corporation | Dallas, TX 75235 | Oil & Gas Operator | May 2025 |
| 387 | Vista Resources, Inc. (A) | Midland, TX 79701 | Oil & Gas Operator | Feb 2000 |
| 388 | Walkabout Operating, LLC | Lubbock, TX 79424 | Oil & Gas Operator | May 2025 |
| 389 | Walsh & Watts Inc | Aledo, TX 76008 | Oil & Gas Operator | May 2025 |
| 390 | Walsh Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2022 |
| 391 | Wapiti Energy, LLC | Houston, TX 77024 | Oil & Gas Operator | Jul 2006 |
| 392 | Wellstar Corporation | Northglenn, CO 80233 | Oil & Gas Operator | Mar 2025 |
| 393 | Westerly Exploration, Inc. | Houston, TX 77256 | Oil & Gas Operator | May 2025 |
| 394 | Westport Oil & Gas Company LP | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2007 |
| 395 | Wheeler Operating Corporation | Fort Worth, TX 76101 | Oil & Gas Operator | May 2025 |
| 396 | White Rock Oil & Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 397 | White, E. C. Oil Co. | Whiteface, TX 79379 | Oil & Gas Operator | Nov 2012 |
| 398 | Wilco Properties, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jan 2004 |
| 399 | Willow Creek Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2009 |
| 400 | Winchester Energy Operating Co. | Austin, TX 78746 | Oil & Gas Operator | May 2025 |