| 301 | Dow Mineral & Royalty Co, Inc | | Oil & Gas Operator | Jun 1994 |
| 302 | Doyle Dempsey | | Oil Operator | May 1997 |
| 303 | DRD Operating Company | | Oil & Gas Operator | Feb 2014 |
| 304 | Dual Energy, Inc. | | Oil & Gas Operator | Oct 2022 |
| 305 | Ducharme Oil, LLC | | Oil & Gas Operator | Jan 2025 |
| 306 | Ducote Oil Co. | | Oil & Gas Operator | Sep 1997 |
| 307 | Dula Energy, Inc. | | Oil & Gas Operator | Sep 2002 |
| 308 | Duncan Oil Company | Holliday, TX 76366 | Oil Operator | Mar 2008 |
| 309 | Dvi | | Oil Operator | Dec 2008 |
| 310 | Dykes Oil Co. | | Oil Operator | Dec 2001 |
| 311 | Dzurik Interests, Inc. | | Oil & Gas Operator | Dec 2024 |
| 312 | E Texas Production MGMT Co Inc | | Oil & Gas Operator | Oct 1996 |
| 313 | E. & H. Oil Company | Woodson, TX 76491 | Oil & Gas Operator | May 1998 |
| 314 | E. Conway Butts, Inc. | | Oil & Gas Operator | Apr 1991 |
| 315 | E. G. Williamson, Jr. | | Oil Operator | Jan 1993 |
| 316 | E2 Operating LLC | Tulsa, OK 74135 | Oil & Gas Operator | Feb 2026 |
| 317 | Eads Operating Company | | Oil & Gas Operator | Mar 1991 |
| 318 | Eagle Oil & Gas, Inc. | | Oil & Gas Operator | Nov 1984 |
| 319 | Eagle Oil Management Co., LLC | | Oil & Gas Operator | Jan 2023 |
| 320 | Earl Dyess | | Oil & Gas Operator | Jul 1990 |
| 321 | Earl W Todd | | Oil Operator | Jan 2008 |
| 322 | Eason Petroleum Company | | Oil & Gas Operator | Jul 2016 |
| 323 | East Texas Exploration, LLC | Edmond, OK 73003 | Oil & Gas Operator | Sep 2019 |
| 324 | Eclipse Petroleum Corporation | La Grange, TX 78945 | Oil & Gas Operator | Aug 2003 |
| 325 | Egh Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 326 | El Paso E&P Company, L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2013 |
| 327 | Eland Energy Inc | Dallas, TX 75248 | Oil & Gas Operator | Dec 2025 |
| 328 | Eleuterius Company | | Oil Operator | Jan 1983 |
| 329 | Elgie Company, Inc. | | Oil & Gas Operator | Aug 1993 |
| 330 | Elgin Energy Corp. | | Oil Operator | May 1995 |
| 331 | Empresa Energy IV, LLC | | Oil & Gas Operator | Aug 2019 |
| 332 | Empresa Energy, LP | Houston, TX 77024 | Oil & Gas Operator | Jul 2009 |
| 333 | Empresa Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 334 | Enable Midstream Partners, LP | Oklahoma City, OK 73124 | Oil Operator | Sep 2023 |
| 335 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 336 | Encore Operating Louisiana, LLC | | Oil & Gas Operator | Dec 2010 |
| 337 | Endurance Operating LLC | | Oil & Gas Operator | Dec 2024 |
| 338 | Enduro Operating LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2018 |
| 339 | Enerco Exploration & MGMT. Co. | | Oil & Gas Operator | Aug 1981 |
| 340 | Energy Development Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2024 |
| 341 | Energy Finders, Inc. | | Oil & Gas Operator | Dec 1981 |
| 342 | Energy Management Corp. | | Oil & Gas Operator | Apr 1999 |
| 343 | Energy Oil & Gas Corporation | Austin, TX 78746 | Oil & Gas Operator | Feb 2026 |
| 344 | Energy Prod Management Corp | | Oil & Gas Operator | Oct 1991 |
| 345 | Energy Reserves Group | Houston, TX 770563020 | Oil & Gas Operator | Apr 1996 |
| 346 | Energy Sources, Inc. | | Oil & Gas Operator | Nov 1990 |
| 347 | Enervest Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 348 | Engeo Co. | | Oil & Gas Operator | Nov 1986 |
| 349 | English Oil & Gas | | Oil Operator | Sep 2021 |
| 350 | Enpower Resources Inc. | Sugar Land, TX 77479 | Oil & Gas Operator | Feb 2026 |
| 351 | Enron Oil & Gas Company | Houston, TX 77210 | Oil & Gas Operator | Dec 1999 |
| 352 | Ensight IV Energy Management,LLC | Shreveport, LA 71101 | Oil & Gas Operator | Dec 2024 |
| 353 | Ensight Resources, L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2001 |
| 354 | Ensource Inc | Midland, TX 79705 | Oil & Gas Operator | Aug 1998 |
| 355 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Feb 2026 |
| 356 | EP Energy E&P Company, LP | Houston, TX 77210 | Oil & Gas Operator | Jan 2023 |
| 357 | Eram, Inc. | | Oil & Gas Operator | Dec 2024 |
| 358 | Ergon Exploration, Inc. | | Oil & Gas Operator | Jun 2023 |
| 359 | Erin Exploration Associates | | Oil & Gas Operator | Mar 1987 |
| 360 | Ernest Starkey, Jr. | | Oil & Gas Operator | Feb 1985 |
| 361 | Est. Of H. L. Hunt | | Oil & Gas Operator | Jun 1983 |
| 362 | Et Gathering & Processing LLC | Dallas, TX 75225 | Oil Operator | Dec 2024 |
| 363 | Etc Field Services LLC | San Antonio, TX 78258 | Oil Operator | Jun 2018 |
| 364 | Etc Texas Pipeline, LTD. | Dallas, TX 75225 | Oil Operator | Sep 2023 |
| 365 | Etd Oil Co. | | Oil Operator | Oct 1990 |
| 366 | Ethredge & Rhoads Oil Company | | Oil Operator | Dec 2012 |
| 367 | Ethredge Oil Company | | Oil & Gas Operator | Aug 1998 |
| 368 | Ethyl Gas Company, LLC | | Oil Operator | Jan 2025 |
| 369 | Etoco, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 370 | Ettco Enterprises, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2024 |
| 371 | Eucutta Petroleum Inc. | | Oil & Gas Operator | Sep 2000 |
| 372 | Evergreen Operating Co., LTD. | McAllen, TX 78502 | Oil & Gas Operator | Feb 2026 |
| 373 | Excalibur Resources, Inc. | | Oil & Gas Operator | Apr 1986 |
| 374 | Excel Oil & Gas, Inc. | Waxahachie, TX 75168 | Oil & Gas Operator | Feb 2026 |
| 375 | Excelsior Oil Corporation | | Oil & Gas Operator | May 1985 |
| 376 | Exco Operating Company, LP | Dallas, TX 75251 | Oil & Gas Operator | Feb 2026 |
| 377 | Exco Production Company, LP | Dallas, TX 75251 | Oil & Gas Operator | Dec 2009 |
| 378 | Exco/Hgi JV Assets, LLC | Dallas, TX 75251 | Oil & Gas Operator | Jun 2014 |
| 379 | F & F Drilling Company | | Oil Operator | Apr 1991 |
| 380 | F & H Production | | Oil & Gas Operator | Apr 2014 |
| 381 | F R Etchen, Jr | | Oil & Gas Operator | Sep 1985 |
| 382 | F W Rabalais, Inc. | | Oil & Gas Operator | Dec 2014 |
| 383 | F. E. Hargraves | | Oil Operator | Mar 1983 |
| 384 | F.E.Hargraves &Sons DRL.Co.Inc. | | Oil & Gas Operator | Mar 1992 |
| 385 | Fairway Resources Operating, LLC | Southlake, TX 76092 | Oil & Gas Operator | Aug 2022 |
| 386 | Faith Energy, L.L.C. | | Oil & Gas Operator | Jan 2025 |
| 387 | Faith Oil Of Hosston | | Oil Operator | Feb 1996 |
| 388 | Family Oil Company | | Oil Operator | Jan 2025 |
| 389 | Fay A. Williams | | Oil & Gas Operator | Dec 2024 |
| 390 | Fear & Duncan | | Oil Operator | Jul 1979 |
| 391 | Ferry Lake Oil Co. | | Oil & Gas Operator | Jan 2025 |
| 392 | Fite Oil & Gas, Inc. | Shreveport, LA 71163 | Oil & Gas Operator | Feb 2026 |
| 393 | Fitzgerald Production Co. | Oil City, LA 71061 | Oil & Gas Operator | Dec 2024 |
| 394 | Flourison Oil & Gas, LLC | | Oil Operator | Jan 2025 |
| 395 | FMP Operating Company, LTD PTN | | Oil & Gas Operator | Mar 1990 |
| 396 | Fod Oil Company | | Oil Operator | May 1999 |
| 397 | Fontainebleau Operating, LLC | | Oil & Gas Operator | Dec 2024 |
| 398 | Forrest Exploration & Dev, LLC | | Gas Operator | May 2003 |
| 399 | Fortune Gas & Oil, Inc. | | Oil & Gas Operator | Apr 2004 |
| 400 | Fortune Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Feb 2026 |