| 301 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 302 | Lone Star Gas Co. | Dallas, TX 75201 | Oil & Gas Operator | Jul 1999 |
| 303 | Lone Star Operations LLC | Lubbock, TX 79401 | Oil & Gas Operator | Apr 2025 |
| 304 | Longfellow Energy, LP | Dallas, TX 75225 | Oil & Gas Operator | Apr 2025 |
| 305 | Lovelady, I. W. | Albuquerque, NM 87111 | Oil & Gas Operator | Jan 1996 |
| 306 | Lynx Energy Company, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Mar 2008 |
| 307 | Lynx Operating Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Apr 2025 |
| 308 | Lytle Creek Operating, Inc. | Abilene, TX 79606 | Oil & Gas Operator | Apr 2025 |
| 309 | M-Tex Resources, Inc. | Merkel, TX 79536 | Oil & Gas Operator | Apr 2025 |
| 310 | M. S. Productions, Inc. | Pittsburg, KS 66762 | Oil & Gas Operator | Nov 2019 |
| 311 | M.R.M. Operating, Inc. | Midland, TX 79707 | Oil & Gas Operator | Aug 2003 |
| 312 | Magnum Production & Well Service | Iowa Park, TX 76367 | Oil & Gas Operator | Apr 2025 |
| 313 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 314 | Manhattan Petroleum, Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 315 | Manzanita Corporation | Midland, TX 79710 | Oil & Gas Operator | Nov 2008 |
| 316 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 317 | Markay Oil & Gas Company | Midland, TX 79701 | Oil & Gas Operator | Sep 1998 |
| 318 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 319 | Marshall R. Young Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2025 |
| 320 | Maxwell, Riley G., Co. | Abilene, TX 79604 | Oil & Gas Operator | Jan 2000 |
| 321 | McCann Corporation | Midland, TX 79710 | Oil & Gas Operator | Apr 2025 |
| 322 | McCracken, H. L. Company | Wichita Falls, TX 76302 | Oil & Gas Operator | Apr 2025 |
| 323 | McGowen Resources Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2003 |
| 324 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 325 | MDM Energy, Inc. | The Colony, TX 75056 | Oil & Gas Operator | Apr 2025 |
| 326 | Mercury Exploration Co | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 327 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | Apr 2025 |
| 328 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 329 | Merrico Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2008 |
| 330 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 331 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2025 |
| 332 | Mid-Tex Energy Inc. | Costa Mesa, CA 92626 | Oil & Gas Operator | Jan 1999 |
| 333 | Midland Oil And Gas, Inc. | Midland, TX 79705 | Oil & Gas Operator | Apr 2025 |
| 334 | Midland Res. Oper. Co., Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 1998 |
| 335 | Midwestern Energy | Mankato, MN 56003 | Oil & Gas Operator | Apr 2025 |
| 336 | Millennium Minerals Corporation | Fredericksbrg, TX 78624 | Oil Operator | Apr 2025 |
| 337 | Miller Oil & Gas, LLC | Snyder, TX 79549 | Oil & Gas Operator | Apr 2025 |
| 338 | Minute Hand LLC | Brenham, TX 77834 | Oil & Gas Operator | Apr 2025 |
| 339 | Miocene Oil & Gas, LTD. | Englewood, CO 80110 | Oil & Gas Operator | Apr 2025 |
| 340 | Miresco, Inc. | Houston, TX 77060 | Oil & Gas Operator | Jan 1995 |
| 341 | MMG Oil Company | Buffalo Gap, TX 79508 | Oil & Gas Operator | Aug 2006 |
| 342 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2025 |
| 343 | Modern Exploration, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Apr 2025 |
| 344 | Mokan Capital, LLC | Spicewood, TX 78669 | Oil Operator | Apr 2025 |
| 345 | Momentum Operating Co., Inc. | Albany, TX 76430 | Oil & Gas Operator | Apr 2025 |
| 346 | Montclair Production Company | Austin, TX 78755 | Oil & Gas Operator | Apr 2025 |
| 347 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 348 | Morris, W. Dale Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Apr 2025 |
| 349 | Mosaic Texas LLC | Dallas, TX 75205 | Oil & Gas Operator | Apr 2025 |
| 350 | Mr Oil Company | Monahans, TX 79756 | Oil & Gas Operator | Nov 2004 |
| 351 | Muirfield Resources Company | Tulsa, OK 74101-3166 | Oil & Gas Operator | Jun 2024 |
| 352 | Mulloy Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 353 | Munn, W. H. Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2002 |
| 354 | Musselman, Owen & King Oper.,Inc | Houston, TX 77002 | Oil & Gas Operator | Feb 1998 |
| 355 | Myco Energy, Inc. | San Angelo, TX 76906 | Oil & Gas Operator | Dec 2003 |
| 356 | National Energy Group, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 357 | Natural Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Jul 1997 |
| 358 | Naumann Oil & Gas, Inc. | Austin, TX 78716 | Oil & Gas Operator | Apr 2025 |
| 359 | Nbi Services, Inc. | Tulsa, OK 74159 | Oil & Gas Operator | Apr 2025 |
| 360 | NBL Permian LLC | Houston, TX 77070 | Oil & Gas Operator | Aug 2018 |
| 361 | Nec Operating, LLC | Southlake, TX 76092 | Oil & Gas Operator | Apr 2025 |
| 362 | Neeb, H. L. | Abilene, TX 79606 | Oil & Gas Operator | Jul 1994 |
| 363 | Newton Corp.,The | Dallas, TX 75251 | Oil & Gas Operator | Apr 2025 |
| 364 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | Apr 2025 |
| 365 | North American Drilling Corp | Plano, TX 75093 | Oil & Gas Operator | Apr 2025 |
| 366 | North American Exploration Co. | Abilene, TX 79602 | Oil & Gas Operator | Apr 1998 |
| 367 | Northland Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2003 |
| 368 | Northstar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 369 | O & G Energy, Inc. | Abilene, TX 79608 | Oil & Gas Operator | Oct 1996 |
| 370 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Apr 2025 |
| 371 | O'Ryan Oil And Gas | Odessa, TX 79768 | Oil & Gas Operator | Apr 2025 |
| 372 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Apr 2025 |
| 373 | Occidental Energy Company, Inc. | Houston, TX 77282 | Oil & Gas Operator | Jul 2021 |
| 374 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | Apr 2025 |
| 375 | Ogs Operating Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2008 |
| 376 | Ohlhausen Oil Company | Abilene, TX 79608 | Oil & Gas Operator | Apr 2025 |
| 377 | Oil Rock Resources, LLC | Weatherford, TX 76088 | Oil & Gas Operator | Jan 2024 |
| 378 | Older Than Dirt LLC | Palo Pinto, TX 76484 | Oil & Gas Operator | Apr 2025 |
| 379 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 380 | Pace Production Co. | San Angelo, TX 76902 | Oil & Gas Operator | Apr 2025 |
| 381 | Paint Rock Operating, LLC | San Angelo, TX 76904 | Oil & Gas Operator | Apr 2025 |
| 382 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | Apr 2025 |
| 383 | Paradis Investments, L.L.C. | Bellaire, TX 77401 | Oil Operator | Jun 2020 |
| 384 | Paragon Corporation | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 385 | Parallel Petroleum Corporation | Midland, TX 79702 | Oil & Gas Operator | Jan 2010 |
| 386 | Paris Petroleum Corporation | Bellaire, TX 77402 | Oil & Gas Operator | Oct 1997 |
| 387 | Parish, John R. | Andrews, TX 79714 | Oil & Gas Operator | Apr 2025 |
| 388 | Parmer, I. A. | Abilene, TX 79606 | Oil & Gas Operator | Oct 1993 |
| 389 | Patriot Resources, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 390 | Patterson Petroleum LP | Snyder, TX 79550 | Oil & Gas Operator | Mar 2008 |
| 391 | Patterson Petroleum, Inc. | Snyder, TX 79550 | Oil & Gas Operator | Feb 2000 |
| 392 | Patterson, Ben M., Jr. | San Antonio, TX 78216 | Oil & Gas Operator | Mar 2003 |
| 393 | Patton Exploration, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 394 | Patton, E. N. Oil Company, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2025 |
| 395 | Patton, Lloyd | Fort Worth, TX 76113 | Oil & Gas Operator | Aug 2003 |
| 396 | Payne-Johnston & Byars | Tyler, TX 75702 | Oil & Gas Operator | Jun 1997 |
| 397 | Pearl, Bill H. Productions, Inc. | Corpus Chrsti, TX 78460 | Oil & Gas Operator | Apr 2025 |
| 398 | Pecos Valley Management Co. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2008 |
| 399 | Pendragon Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Apr 2025 |
| 400 | Penroc Oil Corp. | Hobbs, NM 88241 | Oil & Gas Operator | Feb 2025 |