| 501 | Mash Oilfield Services, LP | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 502 | Mattox, J. R. | Jacksboro, TX 76458 | Oil Operator | Mar 2018 |
| 503 | Mayco Oil | Nocona, TX 76255 | Oil & Gas Operator | Apr 2024 |
| 504 | Mayfield Engineering Service | Tulsa, OK 74104 | Oil & Gas Operator | Apr 2024 |
| 505 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 506 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | Apr 2024 |
| 507 | MB Operating | Wichita Falls, TX 76309 | Oil & Gas Operator | Mar 2008 |
| 508 | McClymond, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2001 |
| 509 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 510 | McCommons Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2024 |
| 511 | McCormick Operating, L.L.C. | Olney, TX 76374 | Oil Operator | Sep 2015 |
| 512 | McCracken, H. L. Company | Wichita Falls, TX 76302 | Oil & Gas Operator | Apr 2024 |
| 513 | McCutchin Petroleum Corporation | Dallas, TX 75225 | Oil & Gas Operator | Apr 2024 |
| 514 | McDay Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | Apr 2024 |
| 515 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 516 | McEuen, Billy Oil Co. | Bowie, TX 76230 | Oil & Gas Operator | Dec 2016 |
| 517 | McEver Oil Company Inc. | Austin, TX 78789 | Oil & Gas Operator | Mar 2008 |
| 518 | MCG Oil & Gas Operating, LLC | Archer City, TX 76351 | Oil & Gas Operator | Sep 2023 |
| 519 | McKee, Kenneth W. Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 520 | McMahon-Bullington Drilling Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 1996 |
| 521 | McMahon-Bullington LP | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2009 |
| 522 | Meeker, Dan Management, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Aug 2007 |
| 523 | Melrose Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2011 |
| 524 | Menasco, J. | Wichita Falls, TX 76310 | Oil & Gas Operator | Dec 2019 |
| 525 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2024 |
| 526 | Metis Energy LLC | Friendswood, TX 77546 | Oil & Gas Operator | Apr 2024 |
| 527 | MHM Oil Co. | Dallas, TX 75240 | Oil & Gas Operator | Oct 2002 |
| 528 | MHM Pipeline Co., Inc. | Dallas, TX 75252 | Oil & Gas Operator | Apr 2024 |
| 529 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 530 | Miles Production Co. | Argyle, TX 76226 | Oil & Gas Operator | Mar 2008 |
| 531 | Miller, Bob I. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 532 | Mills Oil & Gas | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 533 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 534 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 535 | MKS Consulting Corporation | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2005 |
| 536 | MKS Natural Gas Company | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2016 |
| 537 | Mna Enterprises LTD. Co. | Hobbs, NM 88242 | Oil & Gas Operator | Apr 2024 |
| 538 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 539 | Mobil Petro Vac, Inc. | Duncan, OK 73533 | Oil & Gas Operator | Apr 2024 |
| 540 | Mobile Petrovac, Inc. | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2024 |
| 541 | Mohican Exploration, LLC | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 542 | Mokan Capital, LLC | Spicewood, TX 78669 | Oil Operator | Apr 2024 |
| 543 | Moller, Herbert T. | Wichita Falls, TX 76301 | Oil & Gas Operator | Aug 2003 |
| 544 | Moore, Stephen Operating | Graham, TX 76450 | Oil & Gas Operator | Jun 2002 |
| 545 | Morgan, C. V. Partnership | Olney, TX 76374 | Oil & Gas Operator | Jan 2009 |
| 546 | Moriah Resources, Inc. | Midland, TX 79704 | Oil & Gas Operator | Mar 2008 |
| 547 | Mortimer Production Company | San Antonio, TX 78209 | Oil & Gas Operator | Apr 2024 |
| 548 | Mosaic Oil LLC | Dallas, TX 75205 | Oil & Gas Operator | Apr 2024 |
| 549 | Mosaic Texas LLC | Dallas, TX 75205 | Oil & Gas Operator | Apr 2024 |
| 550 | Mote Resources, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2004 |
| 551 | Mountain Creek Oil Company, Inc. | Saint Jo, TX 76265 | Oil & Gas Operator | Apr 2024 |
| 552 | Mullin, W. B. | Graham, TX 76450 | Oil & Gas Operator | Sep 1998 |
| 553 | Munson, David M. Inc. | Dallas, TX 75251 | Oil & Gas Operator | Apr 2024 |
| 554 | Murjo Oil & Royalty Company | Fort Worth, TX 76121 | Oil & Gas Operator | Dec 2023 |
| 555 | Myers, A. J. | Jacksboro, TX 76458 | Oil & Gas Operator | Apr 2024 |
| 556 | N. E. Operating Co., Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2013 |
| 557 | Nall Oil & Gas | Mineral Wells, TX 76067 | Oil & Gas Operator | Apr 2024 |
| 558 | Natural Petroleum Company | Overton, TX 75684 | Oil & Gas Operator | Jun 1994 |
| 559 | Nautilus Exploration, Inc. | Farmers BRNCH, TX 75234 | Oil & Gas Operator | Nov 2021 |
| 560 | New Era International | Graham, TX 76450 | Oil & Gas Operator | Sep 2017 |
| 561 | New Horizon Resources LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2024 |
| 562 | Newark E&P Operating, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jun 2017 |
| 563 | Newark Energy LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2011 |
| 564 | Newberry, Charles D Inc | Campbellsvlle, KY 42719 | Oil Operator | Apr 2024 |
| 565 | NHRG Inc | Wichita Falls, TX 76308 | Oil Operator | Apr 2024 |
| 566 | Nichols,Edwin S Explorations Inc | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 567 | Nitschke, Dan E. | Henrietta, TX 76365 | Oil & Gas Operator | Apr 2024 |
| 568 | Nordan Oil & Gas Corporation | Abilene, TX 79604 | Oil & Gas Operator | Feb 2018 |
| 569 | North Central Texas Energy LLC | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 570 | North Texas Plugging, LLC | Denton, TX 76205 | Oil & Gas Operator | Apr 2024 |
| 571 | Northridge Exploration, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2024 |
| 572 | Northridge Oil Company | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2024 |
| 573 | Northwest Oil Company | Dallas, TX 75204 | Oil & Gas Operator | Jun 2014 |
| 574 | NT Minerals, LLC | Tulsa, OK 74172 | Oil & Gas Operator | Apr 2024 |
| 575 | Nytex Petroleum, Inc. | Graham, TX 76450 | Oil & Gas Operator | Feb 2014 |
| 576 | O.G.P. Operating, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Apr 2024 |
| 577 | Oakmont Oil And Gas | Graham, TX 76450 | Oil Operator | Apr 2024 |
| 578 | Oakridge Oil And Gas, LP | Jacksboro, TX 76458 | Oil & Gas Operator | Apr 2024 |
| 579 | Oklahoma Petroleum Allies LLC | Ardmore, OK 73401 | Oil Operator | Oct 2023 |
| 580 | Okreek Oil Company | Weatherford, TX 76086 | Oil & Gas Operator | Apr 2024 |
| 581 | Ole, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2003 |
| 582 | Owl Creek Operating Co., Inc. | Denver, CO 80206 | Oil & Gas Operator | Apr 2024 |
| 583 | Owl Creek Production Co., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2006 |
| 584 | Owl Creek Production Co., LLC | Denver, CO 80265 | Oil & Gas Operator | Jan 2006 |
| 585 | Oxenergy Incorporated | Flower Mound, TX 75022 | Oil & Gas Operator | Apr 2024 |
| 586 | Oxxn | Weatherford, TX 76086 | Oil & Gas Operator | Oct 2023 |
| 587 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 588 | Oxy USA WTP LP | Houston, TX 77046 | Oil & Gas Operator | Apr 2024 |
| 589 | P & M Construction | Graham, TX 76450 | Oil & Gas Operator | Apr 2024 |
| 590 | P.B. Blue Dot Properties | Wexford, PA 15090 | Oil & Gas Operator | Apr 2024 |
| 591 | Palace Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2007 |
| 592 | Pan Petroleum Corp. | Abilene, TX 79608 | Oil & Gas Operator | Mar 2008 |
| 593 | Panamerican Operating Inc | Dallas, TX 75219 | Oil & Gas Operator | Apr 2024 |
| 594 | Panther City Energy LLC | San Antonio, TX 78205 | Oil & Gas Operator | Apr 2024 |
| 595 | Pardue Oil | Breckenridge, TX 76424 | Oil & Gas Operator | Sep 2006 |
| 596 | Pardue Oil, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Apr 2024 |
| 597 | Paschal Petroleum, Inc. | Dallas, TX 75380 | Oil & Gas Operator | Apr 1994 |
| 598 | Patton Exploration, Inc. | Abilene, TX 79604 | Oil & Gas Operator | Apr 2024 |
| 599 | Pautsky, Jimmy | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2024 |
| 600 | Peba Oil & Gas Co. | Wichita Falls, TX 76302 | Oil & Gas Operator | Jun 2015 |