| 301 | Reserve Operating Corp. | Houston, TX 77040 | Oil & Gas Operator | May 2025 |
| 302 | Reserve Production, Inc. | Tyler, TX 75713 | Oil & Gas Operator | Mar 2008 |
| 303 | Richey Operating, Inc. | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 304 | Richey Properties, Inc. | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 305 | Ridge Petroleum Inc. | Tyler, TX 75701 | Oil & Gas Operator | May 2025 |
| 306 | Ridley Oil Corporation | Tyler, TX 75702 | Oil & Gas Operator | Nov 1996 |
| 307 | Rippy Oil Company | Tyler, TX 75702 | Oil & Gas Operator | May 2025 |
| 308 | Rising Star Petroleum, L.L.C. | Dallas, TX 75219 | Oil & Gas Operator | Apr 2010 |
| 309 | Riverstone Energy Operating, LLC | Houston, TX 77090 | Oil & Gas Operator | May 2025 |
| 310 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 311 | Road Oil Sales Inc. | Tyler, TX 75711 | Oil Operator | Dec 1984 |
| 312 | Rockcliff Energy Operating LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 313 | Roil Mineral & Land Co. | Dallas, TX 75379 | Oil & Gas Operator | May 2025 |
| 314 | Roosth & Genecov Production Co. | Tyler, TX 75710 | Oil & Gas Operator | Aug 2003 |
| 315 | Roosth Production Co. | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 316 | Rosbottom Production Corp | Shreveport, LA 71134 | Oil & Gas Operator | Dec 2017 |
| 317 | Rose City Resources, LLC | Tyler, TX 75703 | Oil & Gas Operator | May 2025 |
| 318 | Roseland Oil & Gas Inc | Rockwall, TX 75087 | Oil & Gas Operator | Feb 2003 |
| 319 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | May 2025 |
| 320 | Rowan, Al | Van, TX 75790 | Oil & Gas Operator | Apr 2021 |
| 321 | Royal Production Company, Inc. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 322 | RTD Resources, LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 323 | Rusk Co. Well Service Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 324 | Rusk Energy Management, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2008 |
| 325 | Russell - FT. Trinidad Op., LLC | Tyler, TX 75710 | Oil & Gas Operator | May 2025 |
| 326 | Rwa, LLC | Boyd, TX 76023 | Oil & Gas Operator | May 2025 |
| 327 | Ryder Scott Oil Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 2005 |
| 328 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 329 | S.E.D.I. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2015 |
| 330 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 331 | Sabine Pipe, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 332 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 333 | Samson Exploration LLC | Tulsa, OK 74101 | Oil & Gas Operator | Mar 2025 |
| 334 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 335 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 336 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 337 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 338 | Sandhill Production Inc | Shongaloo, LA 71072 | Oil & Gas Operator | Dec 2019 |
| 339 | Santos USA Corp. | Houston, TX 77042 | Oil & Gas Operator | Dec 2008 |
| 340 | Sbog, LLC | Granbury, TX 76048 | Oil & Gas Operator | Feb 2021 |
| 341 | Scheriger Production | Graham, TX 76450 | Oil & Gas Operator | Jun 2006 |
| 342 | Schlachter Operating Corporation | Dallas, TX 75225 | Oil & Gas Operator | May 2025 |
| 343 | Schlachter, David A. | Dallas, TX 75225 | Oil & Gas Operator | Apr 2015 |
| 344 | Schlachter, David A., Estate Of | Dallas, TX 75225 | Oil & Gas Operator | Jan 2000 |
| 345 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | May 2025 |
| 346 | Shaida, John H. | Wichita, KS 67226 | Oil & Gas Operator | May 2025 |
| 347 | Sheer Energy, LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 348 | Shelby Operating, Inc. | Flower Mound, TX 75028 | Oil & Gas Operator | Jul 1997 |
| 349 | Shoco Production LLC | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 350 | Shoco Production, L.P. | Kilgore, TX 75663 | Oil & Gas Operator | May 2020 |
| 351 | Sikes Operating, Inc. | Tyler, TX 75711 | Oil & Gas Operator | Jun 2003 |
| 352 | Siroco Operating Co., Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2010 |
| 353 | Sklar & Phillips Oil Co. | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2000 |
| 354 | Sklar Exploration Company LLC | Shreveport, LA 71101 | Oil & Gas Operator | May 2025 |
| 355 | Smal Energy Corp | Tyler, TX 75710 | Oil & Gas Operator | Oct 1995 |
| 356 | Smith Oil Company | Smackover, AR 71762 | Oil Operator | Dec 2024 |
| 357 | Smith Operating & Management Co. | Shreveport, LA 71161 | Oil & Gas Operator | Feb 2005 |
| 358 | Smith Pipe Of Abilene | Abilene, TX 79608 | Oil & Gas Operator | May 2025 |
| 359 | SND Operating, L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | May 2025 |
| 360 | Sonat Exploration Co. | Houston, TX 77251 | Oil & Gas Operator | Dec 2021 |
| 361 | Sonat Exploration Company -Tyler | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 362 | Sonat Exploration Company-MCR | Houston, TX 77251 | Oil & Gas Operator | Dec 1999 |
| 363 | Sonoran Energy Inc. | Addison, TX 75001 | Oil & Gas Operator | May 2025 |
| 364 | Southerland, Glenn Oil & Gas Co. | Hallsville, TX 75650 | Oil & Gas Operator | Feb 2021 |
| 365 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | May 2025 |
| 366 | Southwestern Energy Prod Co | Houston, TX 77032 | Oil & Gas Operator | Jun 2015 |
| 367 | Spartan Operating Company, Inc. | Tyler, TX 75702 | Oil & Gas Operator | Feb 2013 |
| 368 | Speller Oil Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2025 |
| 369 | Spence, Ralph Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jun 2023 |
| 370 | Spindletop Oil & Gas Co. | Dallas, TX 75230 | Oil & Gas Operator | May 2025 |
| 371 | SSC, Inc. | Lubbock, TX 79408 | Oil & Gas Operator | May 2025 |
| 372 | St. Johns Operating #1 L.P. | Houston, TX 77060 | Oil & Gas Operator | Aug 2023 |
| 373 | St. Mary Land & Exploration Co | Denver, CO 80201 | Oil & Gas Operator | Jun 2010 |
| 374 | Stephens, Autry C. | Midland, TX 79701 | Oil & Gas Operator | Mar 2023 |
| 375 | Stonewall Production Company Inc | Tyler, TX 75702 | Oil & Gas Operator | Aug 2009 |
| 376 | Strand Energy, L.C. | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 377 | Stroud Petroleum, Inc. | Shreveport, LA 71162 | Oil & Gas Operator | May 2025 |
| 378 | Studley Resources Corporation | Humble, TX 77347 | Oil & Gas Operator | Dec 1996 |
| 379 | STZ Petroleum Inc. | Houston, TX 77268 | Oil & Gas Operator | Dec 1997 |
| 380 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | May 2025 |
| 381 | Superior Royalty, LLC | Lindale, TX 75771 | Oil Operator | May 2025 |
| 382 | Supreme Energy Company, Inc. | Abilene, TX 79601 | Oil & Gas Operator | May 2025 |
| 383 | SW Operating, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Sep 2000 |
| 384 | Sydri Operating, LLC | Dallas, TX 75231 | Oil & Gas Operator | May 2025 |
| 385 | Tamarack Petroleum Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 386 | Tanos Exploration II, LLC | Tyler, TX 75701 | Oil & Gas Operator | Sep 2023 |
| 387 | Tanos Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Oct 2018 |
| 388 | Tate, Larry V. Operating, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Apr 2002 |
| 389 | Taubert & Steed | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2001 |
| 390 | Texaco E & P Inc | Houston, TX 77099 | Oil & Gas Operator | May 2025 |
| 391 | Texakoma E & P, LLC | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 392 | Texas Crude, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 1995 |
| 393 | Texas Royalty Corp. | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 394 | Texas Vanguard Oil Company | Austin, TX 78720 | Oil & Gas Operator | Jan 2014 |
| 395 | Texlan Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Nov 1994 |
| 396 | Texlan Oil Company, L.C. | Tyler, TX 75711 | Oil & Gas Operator | Aug 2003 |
| 397 | The Cornell Corporation | Fort Worth, TX 76109 | Oil & Gas Operator | Sep 1993 |
| 398 | Thomas Operating LTD. Co. | Dallas, TX 75220 | Oil & Gas Operator | May 2025 |
| 399 | Thomas, B. K. | Plano, TX 75093 | Oil & Gas Operator | Jan 2008 |
| 400 | Thor Operating Company | Tyler, TX 75710 | Oil & Gas Operator | Dec 1995 |