| 501 | M & A Oil Company, LTD. | Wichita Falls, TX 76307 | Oil & Gas Operator | May 2025 |
| 502 | M & B Oil Company | Holliday, TX 76366 | Oil & Gas Operator | Feb 2025 |
| 503 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | May 2025 |
| 504 | Macha Enterprises, Inc. | Wichita Falls, TX 76309 | Oil Operator | May 2025 |
| 505 | Maddox Operating | Jacksboro, TX 76458 | Oil & Gas Operator | May 2025 |
| 506 | Maddux Oil & Gas | Strawn, TX 76475 | Oil & Gas Operator | May 2025 |
| 507 | Madison And Wright LLC | The Colony, TX 75056 | Oil & Gas Operator | May 2025 |
| 508 | Magnum Production & Well Service | Iowa Park, TX 76367 | Oil & Gas Operator | May 2025 |
| 509 | Mahler & Scott | Ruidoso, NM 88355 | Oil & Gas Operator | Aug 2003 |
| 510 | Mahler, Kelly Operating | Graham, TX 76450 | Oil & Gas Operator | Mar 2017 |
| 511 | Maledon Enterprises | Austin, TX 78738 | Oil & Gas Operator | Feb 1996 |
| 512 | Maranatha Exploration, LP | Wichita Falls, TX 76307 | Oil Operator | Feb 2012 |
| 513 | Marchman, J. E. | Graham, TX 76450 | Oil & Gas Operator | Jul 2009 |
| 514 | Marcon Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2011 |
| 515 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 516 | Marshall Energy, Inc. | Dallas, TX 75243 | Oil & Gas Operator | May 1997 |
| 517 | Marshall, Sam | Granbury, TX 76048 | Oil & Gas Operator | Aug 2010 |
| 518 | Martin Petroleum Corp. | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 519 | Martin, Pat Jr. | Archer City, TX 76351 | Oil & Gas Operator | Dec 2019 |
| 520 | Martis Valley Energy, LLC | Wichita Falls, TX 76310 | Oil Operator | May 2025 |
| 521 | Mash Oilfield Services, LP | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 522 | Massie Oil Company | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 523 | Maverick Properties, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Sep 1994 |
| 524 | Maxum Energy Corp | Plano, TX 75025 | Oil & Gas Operator | Jan 2003 |
| 525 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 526 | Mayo Oil Co. | San Antonio, TX 78209 | Oil & Gas Operator | Feb 2019 |
| 527 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | May 2025 |
| 528 | Mayo, Keith | Wichita Falls, TX 76301 | Oil & Gas Operator | Sep 2009 |
| 529 | McCauley Production | Graham, TX 76450 | Oil Operator | May 2025 |
| 530 | McCormick Operating, L.L.C. | Olney, TX 76374 | Oil Operator | Sep 2015 |
| 531 | McCutchin, Jerry | Dallas, TX 75380 | Oil & Gas Operator | Mar 2008 |
| 532 | McDonald, Joe | Burkburnett, TX 76354 | Oil & Gas Operator | Aug 1995 |
| 533 | MCG Oil & Gas Operating, LLC | Archer City, TX 76351 | Oil & Gas Operator | Sep 2023 |
| 534 | McKee, Kenneth W. Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 535 | McLemore, Laurence | Iowa Park, TX 76367 | Oil & Gas Operator | May 2025 |
| 536 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 537 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 538 | Menasco, J. | Wichita Falls, TX 76310 | Oil & Gas Operator | Dec 2019 |
| 539 | Mercury Exploration Co | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 540 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | May 2025 |
| 541 | Mid Continent Resources, Inc. | Houston, TX 77060 | Oil & Gas Operator | May 2025 |
| 542 | Midland Oil And Gas, Inc. | Midland, TX 79705 | Oil & Gas Operator | May 2025 |
| 543 | Midnite Oil Co. | Wichita Falls, TX 76310 | Oil & Gas Operator | May 2025 |
| 544 | Midwestern Energy | Mankato, MN 56003 | Oil & Gas Operator | May 2025 |
| 545 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 546 | MMD Oil Co. | Olney, TX 76374 | Oil & Gas Operator | Dec 2000 |
| 547 | Mole Hole Prod. | Bridgeport, TX 76426 | Oil Operator | May 2025 |
| 548 | Moller, Herbert T. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2003 |
| 549 | Morgan, C. V. Partnership | Olney, TX 76374 | Oil & Gas Operator | Jan 2009 |
| 550 | Morton, J. V. Oil Co. | Iowa Park, TX 76367 | Oil & Gas Operator | Nov 1999 |
| 551 | Mosaic Oil LLC | Dallas, TX 75205 | Oil & Gas Operator | May 2025 |
| 552 | Mosaic Texas LLC | Dallas, TX 75205 | Oil & Gas Operator | May 2025 |
| 553 | MSB Operating | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 554 | Mullin, W. B. | Graham, TX 76450 | Oil & Gas Operator | Sep 1998 |
| 555 | Mullins, Manuel | Olney, TX 76374 | Oil & Gas Operator | May 2025 |
| 556 | Myers, James B. | Olney, TX 76374 | Oil & Gas Operator | May 2025 |
| 557 | New Horizon Resources LLC | Houston, TX 77057 | Oil & Gas Operator | May 2025 |
| 558 | Newberry, Charles D Inc | Campbellsvlle, KY 42719 | Oil Operator | May 2025 |
| 559 | Newport Operating, LLC | Burkburnett, TX 76354 | Oil Operator | May 2025 |
| 560 | NHRG Inc | Wichita Falls, TX 76308 | Oil Operator | May 2025 |
| 561 | Nichols Oil Co. | Holliday, TX 76366 | Oil & Gas Operator | May 2025 |
| 562 | Nielson & Associates Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 563 | Nitschke, Dan E. | Henrietta, TX 76365 | Oil & Gas Operator | May 2025 |
| 564 | North Texas Plugging, LLC | Denton, TX 76205 | Oil & Gas Operator | May 2025 |
| 565 | Northridge Exploration, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 566 | Northridge Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 567 | Novo Exploration Corporation | Hurst, TX 76053 | Oil & Gas Operator | Jun 2020 |
| 568 | O'Donohoe, Jack | Wichita Falls, TX 76301 | Oil & Gas Operator | May 2002 |
| 569 | O'Neal Operating Company | Wichita Falls, TX 76307 | Oil & Gas Operator | Dec 1999 |
| 570 | Oakridge Energy, Inc. | Wichita Falls, TX 76302 | Oil & Gas Operator | May 2025 |
| 571 | Occidental Energy Company, Inc. | Houston, TX 77282 | Oil & Gas Operator | Jul 2021 |
| 572 | Ole, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2003 |
| 573 | Olney Oil LLC | Boerne, TX 78006 | Oil Operator | May 2025 |
| 574 | Olney Properties, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Sep 2003 |
| 575 | Oltex Production | Idalou, TX 79329 | Oil & Gas Operator | May 2025 |
| 576 | Overton Park Oil & Gas LP | Fort Worth, TX 76109 | Oil & Gas Operator | May 2025 |
| 577 | Oxenergy Incorporated | Flower Mound, TX 75022 | Oil & Gas Operator | May 2025 |
| 578 | P-K Oil Co. | Olney, TX 76374 | Oil & Gas Operator | Aug 2003 |
| 579 | P. R. L. Oil Company | Albany, TX 76430 | Oil & Gas Operator | Apr 2008 |
| 580 | P.B. Blue Dot Properties | Wexford, PA 15090 | Oil & Gas Operator | May 2025 |
| 581 | Pacific Exploration Oper Co, LLC | Houston, TX 77057 | Oil Operator | May 2025 |
| 582 | Palmer Operating LLC | Megargel, TX 76370 | Oil Operator | May 2025 |
| 583 | Palmer Tank Trucks, Inc. | Olney, TX 76374 | Oil & Gas Operator | Mar 2008 |
| 584 | Palmer, James W. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2002 |
| 585 | Palmer, John Inc. | Megargel, TX 76370 | Oil & Gas Operator | Feb 1994 |
| 586 | Palmer, John LLC | Megargel, TX 76370 | Oil & Gas Operator | May 2025 |
| 587 | Palmer, Mike Oil | Megargel, TX 76370 | Oil & Gas Operator | Mar 2021 |
| 588 | Palmer, Scott Oil | Olney, TX 76374 | Oil Operator | Feb 2023 |
| 589 | Palo Pinto Production, Inc. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 1998 |
| 590 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | May 2025 |
| 591 | Pardue Oil | Breckenridge, TX 76424 | Oil & Gas Operator | Sep 2006 |
| 592 | Pardue Oil, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | May 2025 |
| 593 | Parnell Operating | Kamay, TX 76369 | Oil & Gas Operator | May 2025 |
| 594 | Parsley, Amos | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2008 |
| 595 | Pautsky, Jimmy | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2025 |
| 596 | Pautsky, Jimmy Estate Of | Wichita Falls, TX 76308 | Oil Operator | Jan 2022 |
| 597 | Pe - Texas, LLC | Oklahoma City, OK 73113 | Oil Operator | May 2025 |
| 598 | Pecos Country Operating Inc. | N Richlnd HLS, TX 76182 | Oil Operator | May 2025 |
| 599 | Peden, Marshell | Archer City, TX 76351 | Oil & Gas Operator | May 2025 |
| 600 | Penroc Oil Corp. | Hobbs, NM 88241 | Oil & Gas Operator | Feb 2025 |