| 301 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 302 | McClure Oil Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 303 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 304 | McDonnold Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 305 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 306 | McFarland & Scobey, Inc. | El Paso, TX 79947 | Oil & Gas Operator | Jul 2025 |
| 307 | MCM Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Jun 2025 |
| 308 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 309 | Medallion Exploration Corp. | Midvale, UT 84047 | Oil & Gas Operator | Oct 1998 |
| 310 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 311 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2025 |
| 312 | Meritage Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | May 2013 |
| 313 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 314 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 315 | MGM Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 316 | Mid-Continent Energy Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 317 | Mid-Continent Energy, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2020 |
| 318 | Mid-States Operating Company | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 319 | Midenergy Operating, LLC | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 320 | Midkiff, John | Midland, TX 79705 | Oil & Gas Operator | Mar 2008 |
| 321 | Midland Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 322 | Midland Oil And Gas, Inc. | Midland, TX 79705 | Oil & Gas Operator | Jul 2025 |
| 323 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 324 | Mineral Technologies, Inc. | Midland, TX 79704 | Oil & Gas Operator | Jul 2025 |
| 325 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 326 | MLC Co., Inc. | Dallas, TX 75201 | Oil & Gas Operator | Dec 1996 |
| 327 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 328 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Jul 2025 |
| 329 | Mojave Operating Company | Midland, TX 79702 | Oil & Gas Operator | Nov 2002 |
| 330 | Momentum Energy Corporation | Austin, TX 78746 | Oil & Gas Operator | Jul 2025 |
| 331 | Momentum Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2004 |
| 332 | Momentum Operating Co., Inc. | Albany, TX 76430 | Oil & Gas Operator | Jul 2025 |
| 333 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 334 | Mr Oil Company | Monahans, TX 79756 | Oil & Gas Operator | Nov 2004 |
| 335 | Muleshoe Crude, LP | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 336 | Mulloy Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 337 | Mulloy, J. W. Associates, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 2003 |
| 338 | Munn, W. H. Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2002 |
| 339 | Murchison Oil & Gas Inc | Plano, TX 75024 | Oil & Gas Operator | Mar 2024 |
| 340 | Murchison Oil And Gas, LLC | Plano, TX 75024 | Oil & Gas Operator | Feb 2025 |
| 341 | Murex Petroleum Corporation | Humble, TX 77347 | Oil & Gas Operator | May 2025 |
| 342 | Murjo Oil & Royalty Company | Fort Worth, TX 76121 | Oil & Gas Operator | Mar 2025 |
| 343 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 344 | MWS Producing, Inc. | Stanton, TX 79782 | Oil & Gas Operator | Jul 2025 |
| 345 | N & O Oil Co. | Imperial, TX 79743 | Oil & Gas Operator | Jul 2025 |
| 346 | Naumann Oil & Gas, Inc. | Austin, TX 78716 | Oil & Gas Operator | Jul 2025 |
| 347 | NBL Permian LLC | Houston, TX 77070 | Oil & Gas Operator | Aug 2018 |
| 348 | Nearburg Producing Company | Dallas, TX 75380 | Oil & Gas Operator | Jul 2025 |
| 349 | New Height Energy, LLC | Houston, TX 77063 | Oil & Gas Operator | Jul 2025 |
| 350 | Newman Cubed, Inc. | Fort Worth, TX 76147 | Oil & Gas Operator | Jul 2025 |
| 351 | North Central Oil Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2005 |
| 352 | North Operating Company | Canton, TX 75103 | Oil & Gas Operator | Jul 2025 |
| 353 | Northland Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2003 |
| 354 | Northstar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Jun 2024 |
| 355 | O'Benco, Inc. | Shreveport, LA 71136 | Oil & Gas Operator | Jul 2025 |
| 356 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 357 | Oak Prairie Operations, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jul 2025 |
| 358 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 359 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 360 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 361 | Octane Energy Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 362 | Odessa Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 363 | Oga Operating L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2000 |
| 364 | Ogs Operating Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2008 |
| 365 | Ojai Oil Company | Camarillo, CA 93012 | Oil & Gas Operator | Apr 2025 |
| 366 | Okla. Magic Circle Energy Corp. | Shawnee, OK 74801 | Oil & Gas Operator | Jul 2004 |
| 367 | Oklahoma RB Operating Company | Midland, TX 79701 | Oil & Gas Operator | Jan 1998 |
| 368 | Overflow Energy, LLC | Perryton, TX 79070 | Oil & Gas Operator | Jul 2025 |
| 369 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 370 | Oxbow Petroleum, LLC | Midland, TX 79703 | Oil & Gas Operator | May 2025 |
| 371 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 372 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 373 | Oxyrock Operating, LLC | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 374 | Ozark Exploration, Inc. | Dallas, TX 75205 | Oil & Gas Operator | Jul 2025 |
| 375 | P & M Petroleum Management LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 376 | Pacesetter Energy, Inc. | Flower Mound, TX 75028 | Oil & Gas Operator | May 2008 |
| 377 | Pacesetter Energy, LLC | Flower Mound, TX 75028 | Oil & Gas Operator | Jul 2020 |
| 378 | Panada Exploration, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Jun 1996 |
| 379 | Panhandle Oil & Gas Inc | Oklahoma City, OK 73112-5688 | Oil & Gas Operator | May 2007 |
| 380 | Parish, John R. | Andrews, TX 79714 | Oil & Gas Operator | Jul 2025 |
| 381 | Parker & Parsley Acq. Group LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 382 | Parker & Parsley Dev LP | Irving, TX 75039-3745 | Oil & Gas Operator | Mar 2015 |
| 383 | Parker & Parsley Development Co. | Midland, TX 79702 | Oil & Gas Operator | May 1995 |
| 384 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 385 | Parker & Parsley Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Nov 2000 |
| 386 | Parsley Energy Operations, LLC | Irving, TX 75038 | Oil & Gas Operator | Jan 2021 |
| 387 | Patriot Resources, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 388 | Patriot Services, Inc. | Westbrook, TX 79565 | Oil & Gas Operator | Mar 2008 |
| 389 | Patterson Petroleum LP | Snyder, TX 79550 | Oil & Gas Operator | Mar 2008 |
| 390 | Pbex Operations, LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 391 | PDC Energy | Denver, CO 80203 | Oil & Gas Operator | Nov 2012 |
| 392 | PDC-WV-Co Corporation | Denver, CO 80203 | Oil & Gas Operator | Aug 2010 |
| 393 | Ped Oil Corporation | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 394 | Pedco Resources Company | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2008 |
| 395 | Pennzoil Exploration & Production Co. | Carthage, TX 75633 | Oil & Gas Operator | Mar 2008 |
| 396 | Pennzoil Petroleum Company | Houston, TX 77252 | Oil & Gas Operator | Nov 1999 |
| 397 | Penroc Oil Corp. | Hobbs, NM 88241 | Oil & Gas Operator | May 2025 |
| 398 | Perenco LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2005 |
| 399 | Permian Deep Rock Oil Co., LLC | Midland, TX 79702 | Oil & Gas Operator | Jul 2025 |
| 400 | Permian Resources Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |