| 301 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 302 | Maverick Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 303 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 304 | McCabe Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2009 |
| 305 | McCann Corporation | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 306 | McCullis Resources Co., Inc. | Littleton, CO 80161 | Oil & Gas Operator | Aug 2025 |
| 307 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 308 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 309 | McShane, J. Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2004 |
| 310 | MDC Operating, Inc. | Midland, TX 79708 | Oil & Gas Operator | Oct 2022 |
| 311 | Meadco Properties | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 312 | Melzer Exploration Company | Midland, TX 79702-2083 | Oil & Gas Operator | May 2013 |
| 313 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | Dec 2025 |
| 314 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 315 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 316 | Meritage Energy Company LLC | Denver, CO 80202 | Oil & Gas Operator | May 2013 |
| 317 | Mesquite SWD Inc | Carlsbad, NM 88221 | Oil & Gas Operator | Dec 2025 |
| 318 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 319 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 320 | MGM Oil & Gas Company | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 321 | Mid-States Operating Company | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 322 | Midenergy Operating, LLC | Houston, TX 77024 | Oil & Gas Operator | Dec 2025 |
| 323 | Midland Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 324 | Midland Oil And Gas, Inc. | Midland, TX 79705 | Oil & Gas Operator | Dec 2025 |
| 325 | Midland Res. Oper. Co., Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 1998 |
| 326 | Midland TMG Inc. | Midland, TX 79705 | Oil & Gas Operator | Apr 2017 |
| 327 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 328 | Mineral Technologies, Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2025 |
| 329 | Minuja Oil And Gas LLC | Corpus Christi, TX 78401 | Oil & Gas Operator | Sep 1996 |
| 330 | Miranda Energy Corporation | Midland, TX 79705 | Oil & Gas Operator | Jun 2016 |
| 331 | Miresco, Inc. | Houston, TX 77060 | Oil & Gas Operator | Jan 1995 |
| 332 | Mission Exploration, Inc. | Fate, TX 75132 | Oil & Gas Operator | Dec 1987 |
| 333 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 334 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 335 | Mitchell, James - Operator | Lamesa, TX 79331 | Oil & Gas Operator | Mar 2008 |
| 336 | MJM Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 337 | Mojave Operating Company | Midland, TX 79702 | Oil & Gas Operator | Nov 2002 |
| 338 | Momentum Energy Corporation | Austin, TX 78746 | Oil & Gas Operator | Dec 2025 |
| 339 | Momentum Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2004 |
| 340 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 341 | Morningstar Operating LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 342 | Morningstar Partners, L.P. | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2022 |
| 343 | Moss, William Corp. | Dallas, TX 75219 | Oil & Gas Operator | Oct 2002 |
| 344 | Mule Kick Operating LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 345 | Muleshoe Crude, LP | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 346 | Mulloy, J. W. Associates, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 2003 |
| 347 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 348 | MWS Producing, Inc. | Stanton, TX 79782 | Oil & Gas Operator | Dec 2025 |
| 349 | Myco Industries, Inc. | Artesia, NM 88211 | Oil & Gas Operator | Feb 2015 |
| 350 | NBL Permian LLC | Houston, TX 77070 | Oil & Gas Operator | Aug 2018 |
| 351 | Nees, Gordon III | Graham, TX 76450 | Oil & Gas Operator | Jun 2002 |
| 352 | New Height Energy, LLC | Houston, TX 77063 | Oil & Gas Operator | Dec 2025 |
| 353 | Nimrod Petroleum Inc. | Big Spring, TX 79721 | Oil & Gas Operator | Dec 2002 |
| 354 | Nitro Oil & Gas, LLC | Cuero, TX 77954 | Oil & Gas Operator | Dec 2025 |
| 355 | North American Resources Company | Billings, MT 59101 | Oil & Gas Operator | Dec 2019 |
| 356 | Northland Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2003 |
| 357 | O'Benco, Inc. | Shreveport, LA 71136 | Oil & Gas Operator | Dec 2025 |
| 358 | O'Brien, George H. Jr. | Midland, TX 79701 | Oil & Gas Operator | Jun 1994 |
| 359 | O'Neill Properties, LTD. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 360 | Occidental Energy Marketing, Inc. | Houston, TX 77227 | Gas Operator | Sep 2015 |
| 361 | Occidental Permian LTD. | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 362 | Odessa Exploration, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 363 | Odessa Oil Investment Co., Inc. | Odessa, TX 79762 | Oil & Gas Operator | Nov 2016 |
| 364 | Oga Operating L.L.C. | Midland, TX 79702 | Oil & Gas Operator | Jan 2000 |
| 365 | Ogris Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 366 | Ogs Operating Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Sep 2008 |
| 367 | Ogx Resources LLC | Midland, TX 79702 | Oil & Gas Operator | Oct 2011 |
| 368 | Oil Management Corporation | Dallas, TX 75206 | Oil & Gas Operator | Apr 2022 |
| 369 | Omar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2013 |
| 370 | Opal Resources Operating Co.,LLC | Cypress, TX 77429 | Oil & Gas Operator | Jan 2019 |
| 371 | Orbit Crude, Inc. | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 372 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 373 | Osceola Oil & Gas Corporation | Somerset, TX 78069 | Oil & Gas Operator | Aug 1994 |
| 374 | Otb Operating, LLC | Stanton, TX 79782 | Oil & Gas Operator | Dec 2025 |
| 375 | Overflow Energy, LLC | Perryton, TX 79070 | Oil & Gas Operator | Dec 2025 |
| 376 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 377 | Owl Ops II LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 378 | Owl Ops LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 379 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 380 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 381 | Oxyrock Operating, LLC | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 382 | P4 Operating, LLC | Midland, TX 79710 | Oil & Gas Operator | Dec 2025 |
| 383 | Pacific Exploration Oper Co, LLC | Houston, TX 77057 | Oil Operator | Dec 2025 |
| 384 | Pactola Development Co | Tulsa, OK 74159 | Oil & Gas Operator | Sep 2004 |
| 385 | Paloma Natural Gas, LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 386 | Panada Exploration, Inc. | Tulsa, OK 74135 | Oil & Gas Operator | Jun 1996 |
| 387 | Panhandle Oil & Gas Inc | Oklahoma City, OK 73112-5688 | Oil & Gas Operator | May 2007 |
| 388 | Parker & Parsley Acq. Group LLC | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 389 | Parker & Parsley Development Co. | Midland, TX 79702 | Oil & Gas Operator | May 1995 |
| 390 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 391 | Parker & Parsley Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Nov 2000 |
| 392 | Parsley Energy Operations, LLC | Irving, TX 75038 | Oil & Gas Operator | Jan 2021 |
| 393 | Patriot Resources, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2017 |
| 394 | Patterson Petroleum, Inc. | Snyder, TX 79550 | Oil & Gas Operator | Feb 2000 |
| 395 | Pbex Operating, LTD. | Midland, TX 79702 | Oil & Gas Operator | Apr 2017 |
| 396 | Pbex Operations, LLC | Midland, TX 79702 | Oil & Gas Operator | Dec 2025 |
| 397 | Pbex-MCM Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | Dec 2025 |
| 398 | PDC Energy | Denver, CO 80203 | Oil & Gas Operator | Nov 2012 |
| 399 | PDC-WV-Co Corporation | Denver, CO 80203 | Oil & Gas Operator | Aug 2010 |
| 400 | Pecos Operating Company, LLC | Midland, TX 79701 | Oil & Gas Operator | Jun 2021 |