| 301 | Scana Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 302 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 303 | Scana Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2005 |
| 304 | Scoggins Production LLC | Enid, OK 73703-3002 | Oil & Gas Operator | Feb 2025 |
| 305 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 306 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 307 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 308 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 309 | Select Exploration Group LLC | Eufaula, OK 74432 | Oil & Gas Operator | May 2024 |
| 310 | Shell Trading Us Company | Houston, TX 77210 | Oil & Gas Operator | Jan 2025 |
| 311 | Sidwell Oil & Gas, Inc. | Amarillo, TX 79105 | Oil & Gas Operator | Sep 2014 |
| 312 | Siegfried R H Inc | Tulsa, OK 74104 | Oil & Gas Operator | Mar 2008 |
| 313 | Sierra Resources, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Dec 2024 |
| 314 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2025 |
| 315 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2025 |
| 316 | SLT Dakota Operating, Inc. | Yukon, OK 73099 | Oil & Gas Operator | Apr 2025 |
| 317 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Apr 2025 |
| 318 | Smith B R Jr Disposal Co | Erick, OK 73645 | Oil & Gas Operator | Jun 2021 |
| 319 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 320 | Sonata Oil & Gas Corp Inc | Stratford, OK 74812 | Oil & Gas Operator | Apr 2014 |
| 321 | Sooner Exploration & Development Co Inc | Enid, OK 73702-3525 | Oil & Gas Operator | Oct 2023 |
| 322 | Sooner Oil & Gas | Fairview, OK 73737-1806 | Oil & Gas Operator | Jan 2025 |
| 323 | Sooner Oil & Gas Management Inc | Crescent, OK 73028 | Oil & Gas Operator | Feb 2025 |
| 324 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 325 | Southwest Energy LP | Houston, TX 77002 | Oil & Gas Operator | Jan 2025 |
| 326 | Special Energy Corporation | Stillwater, OK 74076 | Oil & Gas Operator | Apr 2025 |
| 327 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 328 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Feb 2025 |
| 329 | Stewart K Petroleum Corp | Edmond, OK 73013 | Oil & Gas Operator | Mar 2015 |
| 330 | Sundown Energy LP | Dallas, TX 75248 | Oil & Gas Operator | Apr 2025 |
| 331 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 332 | Sunnybook Transmission Inc | Houston, TX 77002 | Oil & Gas Operator | Oct 1992 |
| 333 | Sunrise Energy Co | Dallas, TX 75206 | Oil & Gas Operator | Aug 1993 |
| 334 | Sweetwater Exploration LLC | Norman, OK 73069-5636 | Oil & Gas Operator | Jan 2025 |
| 335 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 336 | SWN Production LLC | Spring, TX 77389-4954 | Oil & Gas Operator | Feb 2022 |
| 337 | T & O Gas Co | | Oil Operator | May 2001 |
| 338 | Tapstone Energy LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2025 |
| 339 | Te-Ray Resources, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Apr 2025 |
| 340 | Tecolote Energy Operating, LLC | Fort Worth, TX 76107 | Oil & Gas Operator | Jan 2024 |
| 341 | Temex Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Feb 2002 |
| 342 | Templar Operating LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2025 |
| 343 | Tenaska Marketing Ventures | Omaha, NE 68154 | Oil & Gas Operator | Mar 2021 |
| 344 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Dec 2024 |
| 345 | Teocalli Exploration LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2025 |
| 346 | Terra Production Company | Okemah, OK 74859-5924 | Oil & Gas Operator | Apr 2020 |
| 347 | Tex/Con Oil & Gas Company | Houston, TX 77074 | Oil & Gas Operator | Feb 2001 |
| 348 | Texaco Expl. And Prod. Inc. | Houston, TX 77236 | Oil & Gas Operator | Feb 2025 |
| 349 | Texas Southwest Gas LLC | Tulsa, OK 74121 | Oil & Gas Operator | Oct 2022 |
| 350 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 351 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | Feb 2025 |
| 352 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 353 | Titan Resources LTD | Limaville, OH 44640 | Oil & Gas Operator | Feb 2025 |
| 354 | Tomlinson Oil Co. Inc. | Great Bend, KS 67530 | Oil & Gas Operator | Jun 2023 |
| 355 | Torch Operating Company | Houston, TX 77010 | Oil & Gas Operator | Mar 2015 |
| 356 | Total Petroleum Inc | Denver, CO 80201-0500 | Oil & Gas Operator | Nov 2006 |
| 357 | Totalfinaelf E&P USA Inc | Houston, TX 77024 | Oil & Gas Operator | Jul 2007 |
| 358 | Trans Oil Marketing LLC | Abilene, TX 79608 | Oil Operator | Aug 2023 |
| 359 | Transok LLC | Oklahoma City, OK 73124-0300 | Oil & Gas Operator | Jul 2020 |
| 360 | Trigg Drilling Company Inc | Oklahoma City, OK 73105 | Oil & Gas Operator | Jan 2013 |
| 361 | Trigger'S Disposal LLC | Sayre, OK 73662-2913 | Oil Operator | Sep 2022 |
| 362 | Triple "S" Gas, Inc. | Louisville, KY 40255 | Oil & Gas Operator | Apr 2025 |
| 363 | Trissell Alva Lee | Willow, OK 73673-9602 | Oil Operator | Apr 2020 |
| 364 | Troy Energy Operating LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Feb 2025 |
| 365 | Txo Production Corp. | Ganado, TX 77962 | Oil & Gas Operator | Aug 2022 |
| 366 | Txok Energy Resources Company | Tulsa, OK 74172-0140 | Oil & Gas Operator | Feb 2017 |
| 367 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 368 | Unbridled Resources, LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2025 |
| 369 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 370 | Union Texas Petroleum Corp. | Houston, TX 77252-2120 | Oil & Gas Operator | Dec 2014 |
| 371 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2025 |
| 372 | United Energy Operating, LLC | Edmond, OK 73083 | Oil & Gas Operator | Apr 2025 |
| 373 | United Oil Corporation | Denver, CO 80202-3813 | Oil & Gas Operator | Jan 2025 |
| 374 | Urban Oil & Gas Group, LLC | Plano, TX 75074 | Oil & Gas Operator | Apr 2025 |
| 375 | V S Oil Company | Burkburnett, TX 76354 | Oil & Gas Operator | Apr 2025 |
| 376 | Valence Operating Company | Kingwood, TX 77339 | Oil & Gas Operator | Apr 2025 |
| 377 | Valero Marketing & Supply Co | San Antonio, TX 78269-6000 | Oil & Gas Operator | Sep 2023 |
| 378 | Vastar Resources Inc | Houston, TX 77253 | Oil & Gas Operator | Dec 2024 |
| 379 | Venis Exploration Company | Aledo, TX 76008 | Oil & Gas Operator | Oct 2024 |
| 380 | Wacker Oil Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 1996 |
| 381 | Wagner & Brown | Midland, TX 79702 | Oil & Gas Operator | Aug 2014 |
| 382 | Wallace Oil & Gas Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | Apr 2025 |
| 383 | Walsh Jr F Howard | Fort Worth, TX 76102-4773 | Oil & Gas Operator | Jan 2025 |
| 384 | Ward Petroleum Corporation | Enid, OK 73702 | Oil & Gas Operator | Jan 2025 |
| 385 | Warren American Oil Company LLC | Tulsa, OK 74147 | Oil & Gas Operator | Apr 2025 |
| 386 | Weststar Oil & Gas Inc | Edmond, OK 73013 | Oil & Gas Operator | Feb 2025 |
| 387 | Wheeler Midstream LLC | Houston, TX 77002 | Oil & Gas Operator | May 2018 |
| 388 | Wildcat Cement Co. | Shamrock, TX 79079 | Oil & Gas Operator | May 2015 |
| 389 | Williams Doyle Dba BCF Gas | Tulsa, OK 74114-7099 | Oil & Gas Operator | Jul 2023 |
| 390 | Williford Energy Company | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2025 |
| 391 | Willow Pipeline Co | Wetherford, OK 73096 | Oil & Gas Operator | Feb 2002 |
| 392 | Windsor Energy Group LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Aug 2021 |
| 393 | WM Energy Corporation | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2015 |
| 394 | Wynn-Crosby Operating LP | Dallas, TX 75201 | Oil & Gas Operator | Jan 2025 |
| 395 | Xanadu Exploration Company | Broken Arrow, OK 74014 | Oil & Gas Operator | Feb 2025 |
| 396 | Xeric Oil & Gas Corporation | Midland, TX 79702 | Oil & Gas Operator | Apr 2014 |
| 397 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2025 |
| 398 | Yale Oil Association, Inc. | Oklahoma City, OK 73105 | Oil & Gas Operator | Feb 2025 |
| 399 | Yarhola Production Company | Drumright, OK 74030 | Oil & Gas Operator | Feb 2025 |