| 301 | R. W. Henry | | Oil & Gas Operator | Dec 1999 |
| 302 | Raak-Wilson Properties | | Oil & Gas Operator | Dec 1999 |
| 303 | Rare Petro Exploration LLC | | Oil & Gas Operator | Dec 2025 |
| 304 | Razar Resources | | Oil & Gas Operator | Dec 2000 |
| 305 | Redbank Oil Co. | | Oil Operator | Nov 2025 |
| 306 | Redbank Oil Co. Operator | | Oil Operator | Nov 2025 |
| 307 | Reserve Petroleum California Inc. | | Oil & Gas Operator | Nov 2025 |
| 308 | Rio Bravo Poso | | Oil & Gas Operator | Dec 2009 |
| 309 | Road Oil Sales Inc. | Tyler, TX 75711 | Oil Operator | Dec 1984 |
| 310 | Robert E. & Ruby C. Beasley Trustees | | Oil & Gas Operator | Dec 1990 |
| 311 | Rothschild Oil Co. | | Oil Operator | Dec 1982 |
| 312 | Roya Resources LLC | | Oil & Gas Operator | Mar 2022 |
| 313 | Royale Energy Inc | San Diego, CA 92108-4518 | Oil & Gas Operator | Nov 2025 |
| 314 | S & D Energy Associates Inc. | | Gas Operator | Dec 1986 |
| 315 | S & S Oil Company LLC | | Oil Operator | Nov 2025 |
| 316 | S. A. Camp Companies | | Oil & Gas Operator | Dec 1998 |
| 317 | S. H. Montgomery | | Oil & Gas Operator | Dec 1996 |
| 318 | Sacramento Energy Inc. | | Oil & Gas Operator | Nov 2025 |
| 319 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |
| 320 | San Joaquin Facilities Management Inc. | | Oil & Gas Operator | Dec 2025 |
| 321 | Say Energy Inc. | | Oil & Gas Operator | Dec 2004 |
| 322 | Second Wind Production Company Inc. | | Oil Operator | Dec 2013 |
| 323 | Seneca Resources Co LLC | Cranberry Township, PA 16066 | Oil & Gas Operator | Dec 2025 |
| 324 | Seneca Western Minerals Corp. | | Oil & Gas Operator | Dec 2009 |
| 325 | Sentinel Peak Resources California LLC | | Oil & Gas Operator | Dec 2025 |
| 326 | Sequoia Exploration Inc. | | Oil & Gas Operator | Nov 2025 |
| 327 | Shadow Wolf Energy LLC | | Oil Operator | Dec 2025 |
| 328 | Shell Calif. Prod. Inc. | | Oil Operator | Dec 1980 |
| 329 | Shell Western E&P Inc. | Houston, TX 77001 | Oil & Gas Operator | May 2011 |
| 330 | Shelly Energy Inc | Berwyn, PA 19312 | Oil & Gas Operator | Dec 2025 |
| 331 | Sherman Havens | | Oil & Gas Operator | Nov 2025 |
| 332 | Sierra Resources, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Dec 2025 |
| 333 | Signal Hill Petroleum Inc. | | Oil & Gas Operator | Dec 2025 |
| 334 | SJM Oil LLC | | Oil & Gas Operator | Dec 2009 |
| 335 | Soc Resources Inc. | | Oil & Gas Operator | Dec 2024 |
| 336 | Sojitz Energy Venture, Inc. | Houston, TX 77042 | Oil & Gas Operator | Feb 2018 |
| 337 | Solimar Energy LLC | | Oil & Gas Operator | Nov 2025 |
| 338 | Son Petroleum | Bakersfield, CA 93309 | Oil & Gas Operator | Mar 1994 |
| 339 | Source Energy Corp. | | Gas Operator | Aug 2022 |
| 340 | Southern California Gas Company | | Oil & Gas Operator | Dec 2025 |
| 341 | Standing Bear Petroleum Inc. | | Oil & Gas Operator | Dec 2005 |
| 342 | Stockdale Oil & Gas Inc. | | Oil & Gas Operator | Dec 2001 |
| 343 | Stowe Killingsworth | | Oil & Gas Operator | Apr 2023 |
| 344 | Strata-X Inc. | | Oil & Gas Operator | Nov 2025 |
| 345 | Stream Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | Nov 2025 |
| 346 | Summit Energy LLC | | Oil & Gas Operator | Dec 2025 |
| 347 | Sun Mountain Oil & Gas | | Oil & Gas Operator | Dec 2020 |
| 348 | Sunray Petroleum Inc. | | Oil & Gas Operator | Nov 2025 |
| 349 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 350 | Superior Well Service Inc. | | Oil & Gas Operator | Sep 2007 |
| 351 | Synergy Resources | Artesia, NM 88210 | Oil & Gas Operator | Jan 2015 |
| 352 | Tamarack Energy Inc | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 353 | Tannehill Oil Company | | Oil & Gas Operator | Dec 1991 |
| 354 | Target Drilling | | Oil & Gas Operator | Feb 2018 |
| 355 | Team Operating, L.L.C. | Pinehurst, TX 77362 | Oil & Gas Operator | Feb 2026 |
| 356 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Nov 2025 |
| 357 | Tenneco West, Inc. | | Oil & Gas Operator | Dec 1983 |
| 358 | Termo Company Of Texas | | Oil & Gas Operator | Dec 1986 |
| 359 | Tetra Oil Company | | Oil & Gas Operator | Nov 2025 |
| 360 | Texaco Producing Inc. | Rock Springs, WY 82901 | Oil & Gas Operator | Dec 2000 |
| 361 | Texalta Oil And Gas Inc. | | Gas Operator | Dec 1990 |
| 362 | Texas Crude Energy, Inc. | Houston, TX 77256 | Oil & Gas Operator | Oct 2012 |
| 363 | Texcal Energy (GP) LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2016 |
| 364 | The Arvin Company | | Oil Operator | Dec 2004 |
| 365 | The Harter Family Trust Of 1995 | | Oil Operator | Dec 2003 |
| 366 | The Nahabedian Exploration Group LLC | | Oil & Gas Operator | Nov 2025 |
| 367 | The Termo Company | Long Beach, CA 90801 | Oil & Gas Operator | Dec 2025 |
| 368 | Thomas Oil Company | | Oil & Gas Operator | Dec 2008 |
| 369 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 370 | Tosco Enhanced Oil Recovery Corporation | | Oil Operator | Dec 1981 |
| 371 | Towne Exploration Company LP | | Oil & Gas Operator | Dec 2025 |
| 372 | TRC Cypress Group LLC | | Oil & Gas Operator | Nov 2025 |
| 373 | TRC Operating Company Inc. | | Oil & Gas Operator | Dec 2025 |
| 374 | Tri-Valley Oil & Gas Co. | | Oil & Gas Operator | Nov 2025 |
| 375 | Trident Oil & Gas Corporation Inc. | | Oil & Gas Operator | Dec 1993 |
| 376 | Trio Petroleum LLC | | Oil & Gas Operator | Nov 2025 |
| 377 | Triton Oil & Gas Corp. | Houston, TX 77002 | Oil & Gas Operator | Nov 2014 |
| 378 | TS Leasing Operations Inc. | | Oil & Gas Operator | Dec 2025 |
| 379 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 380 | Underground Energy Inc. | | Oil & Gas Operator | Nov 2025 |
| 381 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 382 | United Energy, Inc. | Wichita, KS 67230 | Oil & Gas Operator | Dec 2002 |
| 383 | Valid Energy Company | | Oil & Gas Operator | Nov 2025 |
| 384 | Valley Energy Resources Inc. | | Oil & Gas Operator | Dec 2006 |
| 385 | Vaquero Energy Inc | Bakersfield, CA 93309 | Oil & Gas Operator | May 2023 |
| 386 | Vaquero SJV LLC | | Oil & Gas Operator | Dec 2022 |
| 387 | Vast Star Corporation | | Oil Operator | Dec 2025 |
| 388 | Venoco LLC | | Oil & Gas Operator | Nov 2025 |
| 389 | Verjill Oil Company | | Oil & Gas Operator | Dec 2025 |
| 390 | Victory Oil Company LLC | | Oil & Gas Operator | Dec 2009 |
| 391 | Vintage Production California LLC | | Oil & Gas Operator | Jun 2016 |
| 392 | Virsal Oil Company | | Oil Operator | Dec 2000 |
| 393 | Walrath Oil Co. LLC | | Oil Operator | Dec 2025 |
| 394 | West American Energy Corporation | | Oil & Gas Operator | Dec 2025 |
| 395 | West Coast Oil Company | | Oil Operator | Dec 1996 |
| 396 | West Energy Operating LLC | | Oil & Gas Operator | Dec 2025 |
| 397 | Western Continental Operating Company | | Oil & Gas Operator | Dec 2007 |
| 398 | Western Discovery USA Inc. | | Oil & Gas Operator | Jan 2018 |
| 399 | Western States International Inc. | | Oil & Gas Operator | Nov 2025 |
| 400 | Whisler Enterprise Company | Erie, CO 80516 | Oil & Gas Operator | Jan 2026 |