| 1 | Madison Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 1998 |
| 2 | Magnum Oil & Gas | Flower Mound, TX 75028 | Oil & Gas Operator | Jul 2000 |
| 3 | Manzanita Corporation | Midland, TX 79710 | Oil & Gas Operator | Nov 2008 |
| 4 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 5 | Marr, M. H. | Dallas, TX 75201 | Gas Operator | Jan 2002 |
| 6 | Marshall Pipe & Supply Co. | Nocona, TX 76255 | Oil & Gas Operator | Mar 2008 |
| 7 | Marshall, Sam | Granbury, TX 76048 | Oil & Gas Operator | Aug 2010 |
| 8 | Marshall, Samuel Meek, Estate Of | Granbury, TX 76048 | Oil & Gas Operator | Oct 2025 |
| 9 | Mash Oilfield Services, LP | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 10 | Massie Oil Company | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 11 | Mayco Oil | Nocona, TX 76255 | Oil & Gas Operator | Oct 2025 |
| 12 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 13 | MB Exploration, LLC | Dallas, TX 75380 | Oil & Gas Operator | Jul 2008 |
| 14 | McCommons Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Oct 2025 |
| 15 | McCormack, Paul H. | Gainesville, TX 76241 | Oil & Gas Operator | Sep 2003 |
| 16 | McCutchin Petroleum Corporation | Dallas, TX 75225 | Oil & Gas Operator | Oct 2025 |
| 17 | McCutchin, Jerry | Dallas, TX 75380 | Oil & Gas Operator | Mar 2008 |
| 18 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 19 | Menasco, J. | Wichita Falls, TX 76310 | Oil & Gas Operator | Dec 2019 |
| 20 | Mercury Exploration Co | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 21 | Merritt Operating, Inc. | Mineola, TX 75773 | Oil & Gas Operator | Oct 2025 |
| 22 | Mesquite SWD Inc | Carlsbad, NM 88221 | Oil & Gas Operator | Oct 2025 |
| 23 | Metzner, Norma J. Estate | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 1998 |
| 24 | Miles Production Co. | Argyle, TX 76226 | Oil & Gas Operator | Mar 2008 |
| 25 | Miller Energy Inc | Houston, TX 77024 | Oil & Gas Operator | Oct 2016 |
| 26 | Miller, Glenn J. | Muenster, TX 76252 | Oil & Gas Operator | Jul 2025 |
| 27 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 28 | Modern Exploration, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Oct 2025 |
| 29 | Mote Resources, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2004 |
| 30 | Mountain Creek Oil Company, Inc. | Saint Jo, TX 76265 | Oil & Gas Operator | Oct 2025 |
| 31 | Muenster Drilling Co. Inc. | Muenster, TX 76252 | Oil & Gas Operator | Oct 2025 |
| 32 | Muirfield Exploration, LTD. | Wichita Falls, TX 76301 | Oil & Gas Operator | Oct 2025 |
| 33 | Muirfield Resources Company | Tulsa, OK 74101-3166 | Oil & Gas Operator | Jun 2024 |