| 401 | Last Dollar LLC | Big Lake, TX 76932 | Oil & Gas Operator | May 2025 |
| 402 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 403 | Latigo Oil And Gas Inc | Woodward, OK 73801 | Oil & Gas Operator | Mar 2025 |
| 404 | Lavanco Energy, Inc. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2006 |
| 405 | Lavanco Energy, LTD. | San Angelo, TX 76906 | Oil & Gas Operator | Feb 2024 |
| 406 | Lawrence, C. F. & Assoc. Inc. | Lubbock, TX 79401 | Oil & Gas Operator | May 2025 |
| 407 | LDF Energy, LLC | Midland, TX 79707 | Oil & Gas Operator | May 2025 |
| 408 | Leclair Operating Co., Inc. | Abilene, TX 79602 | Oil & Gas Operator | May 2025 |
| 409 | Leede Oil & Gas Inc. | Greenwood VLG, CO 80111 | Oil & Gas Operator | Aug 2003 |
| 410 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | May 2025 |
| 411 | Lewis, T. K. | Horseshoe Bay, TX 78657 | Oil & Gas Operator | May 2025 |
| 412 | Lillis, Michael D. | Midland, TX 79702 | Oil & Gas Operator | May 2025 |
| 413 | Lindenmuth & Associates Inc | Austin, TX 78703 | Oil & Gas Operator | Aug 2024 |
| 414 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 415 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 416 | Live Oak Gas Company | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 417 | Llano Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 418 | Locin Oil Corporation | Katy, TX 77494 | Oil & Gas Operator | May 2025 |
| 419 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 420 | Longfellow Energy, LP | Dallas, TX 75225 | Oil & Gas Operator | May 2025 |
| 421 | LT Oil Company | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 422 | LTS Oil & Gas | Lubbock, TX 79424 | Oil & Gas Operator | May 2025 |
| 423 | LTS Oil & Gas A | Lubbock, TX 79424 | Oil & Gas Operator | May 2025 |
| 424 | M & G Oil Company | Marble Falls, TX 78654 | Oil & Gas Operator | May 2025 |
| 425 | M.A.R.S. Energy | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 426 | Magnum Hunter Production, Inc. | Irving, TX 75014 | Oil & Gas Operator | Dec 2019 |
| 427 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | May 2025 |
| 428 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 429 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Mar 2025 |
| 430 | Marcum Drilling Co. | Midland, TX 79701 | Oil & Gas Operator | Aug 2002 |
| 431 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 432 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 433 | Marshall R. Young Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 434 | Mas Operating Co. | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 435 | Mathis, Bill | Midland, TX 79702 | Oil & Gas Operator | Nov 2001 |
| 436 | Maverick Operating, LLC | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 437 | Mayjac I, LLC | Midland, TX 79710 | Oil & Gas Operator | May 2025 |
| 438 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 439 | McCabe Energy, Inc. | Midland, TX 79702 | Oil & Gas Operator | Aug 2009 |
| 440 | McCamey Oil And Gas LLC | MC Camey, TX 79752 | Oil Operator | May 2025 |
| 441 | McCurdy Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2025 |
| 442 | McDaniel Oil Co. | Marble Falls, TX 78654 | Oil & Gas Operator | May 2025 |
| 443 | McDaniel, Willard Jr. Oil Co. | Marble Falls, TX 78654 | Oil & Gas Operator | Mar 2005 |
| 444 | McDonnold Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 445 | McFarland & Scobey, Inc. | El Paso, TX 79947 | Oil & Gas Operator | May 2025 |
| 446 | McGuffin, Joe Jr. | Christoval, TX 76935 | Oil & Gas Operator | May 2025 |
| 447 | Memorial Exploration Company | Saint Louis, MO 63105 | Oil & Gas Operator | Aug 1996 |
| 448 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 449 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 450 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 451 | Merrico Resources, Inc. | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2008 |
| 452 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | Mar 2025 |
| 453 | Mesquite SWD Inc | Carlsbad, NM 88221 | Oil & Gas Operator | May 2025 |
| 454 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 455 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 456 | Michaelson Producing Company | MC Camey, TX 79752 | Oil & Gas Operator | May 2025 |
| 457 | Mid-Con Energy Operating, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | May 2020 |
| 458 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2025 |
| 459 | Mid-Continent Energy Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2025 |
| 460 | Midenergy Operating, LLC | Houston, TX 77024 | Oil & Gas Operator | May 2025 |
| 461 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 462 | Millennium Resources, LLC. | Big Lake, TX 76932 | Oil & Gas Operator | Sep 2012 |
| 463 | Mills, Pete | Midland, TX 79707 | Oil & Gas Operator | Sep 2005 |
| 464 | Miltex Oil Company | Boerne, TX 78006 | Oil & Gas Operator | May 2025 |
| 465 | Mineral Technologies, Inc. | Midland, TX 79704 | Oil & Gas Operator | May 2025 |
| 466 | Minute Hand LLC | Brenham, TX 77834 | Oil & Gas Operator | May 2025 |
| 467 | Mission River Systems, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | May 2025 |
| 468 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 469 | MLC Operating, LP | Houston, TX 77063 | Oil & Gas Operator | May 2025 |
| 470 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 471 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | May 2025 |
| 472 | Moleo Gas Corp. | San Angelo, TX 76902 | Oil & Gas Operator | Apr 2018 |
| 473 | Molopo Energy Texas, LLC | Canada, 00100 | Oil & Gas Operator | Jan 2015 |
| 474 | Momentum Energy Corporation | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 475 | Momentum Energy, LLC | Midland, TX 79702 | Oil & Gas Operator | Feb 2004 |
| 476 | Momentum Operating Co., Inc. | Albany, TX 76430 | Oil & Gas Operator | May 2025 |
| 477 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 478 | Moore, J.W. Oil Co | Llano, TX 78643 | Oil Operator | May 2025 |
| 479 | Moore, Kirby | Ozona, TX 76943 | Oil & Gas Operator | Jul 1996 |
| 480 | Morris, W. Dale Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | May 2025 |
| 481 | Mosaic Texas LLC | Dallas, TX 75205 | Oil & Gas Operator | May 2025 |
| 482 | Mulloy Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | May 2025 |
| 483 | MV Purchasing LLC | Wichita, KS 67206 | Oil & Gas Operator | Dec 2019 |
| 484 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 485 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 486 | MWS Producing, Inc. | Stanton, TX 79782 | Oil & Gas Operator | May 2025 |
| 487 | Nadel And Gussman Permian,L.L.C. | Tulsa, OK 74103 | Oil & Gas Operator | May 2025 |
| 488 | NBL Permian LLC | Houston, TX 77070 | Oil & Gas Operator | Aug 2018 |
| 489 | Nearburg Producing Company | Dallas, TX 75380 | Oil & Gas Operator | May 2025 |
| 490 | Newfield Expl. Mid-Con. Inc | Tulsa, OK 74172 | Oil & Gas Operator | Jan 2015 |
| 491 | Newfield Exploration Company | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2017 |
| 492 | Newman Cubed, Inc. | Fort Worth, TX 76147 | Oil & Gas Operator | May 2025 |
| 493 | Newton Corp.,The | Dallas, TX 75251 | Oil & Gas Operator | May 2025 |
| 494 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 495 | Nordstrand Engineering Inc | Houston, TX 77019 | Oil & Gas Operator | May 2025 |
| 496 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 497 | North Lake Resources LLC | Oklahoma City, OK 73132 | Oil & Gas Operator | May 2025 |
| 498 | O & O Operators, LLC. | Fate, TX 75132 | Oil & Gas Operator | May 2025 |
| 499 | O'Brien, George H. Jr. | Midland, TX 79701 | Oil & Gas Operator | Jun 1994 |
| 500 | O'Ryan Oil And Gas | Odessa, TX 79768 | Oil & Gas Operator | May 2025 |