| 1 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | Oct 2025 |
| 2 | Maddux Oil & Gas | Strawn, TX 76475 | Oil & Gas Operator | Oct 2025 |
| 3 | Madison And Wright LLC | The Colony, TX 75056 | Oil & Gas Operator | Oct 2025 |
| 4 | Maranatha Exploration, LP | Wichita Falls, TX 76307 | Oil Operator | Feb 2012 |
| 5 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 6 | Marshall, Sam | Granbury, TX 76048 | Oil & Gas Operator | Aug 2010 |
| 7 | Marshall, Samuel Meek, Estate Of | Granbury, TX 76048 | Oil & Gas Operator | Oct 2025 |
| 8 | Martin Well Service Company | Mineral Wells, TX 76067 | Oil & Gas Operator | Jul 2006 |
| 9 | Mash Oilfield Services, LP | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 10 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | Oct 2025 |
| 11 | McEuen, Billy Oil Co. | Bowie, TX 76230 | Oil & Gas Operator | Dec 2016 |
| 12 | McKee, Kenneth W. Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 13 | McKenzie Operating Company, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 14 | McMahon-Bullington Drilling Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 1996 |
| 15 | McMahon-Bullington LP | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2009 |
| 16 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 17 | Meeker & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 18 | Meeker, Dan Management, Inc. | Fort Worth, TX 76107 | Oil & Gas Operator | Aug 2007 |
| 19 | Melrose Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2011 |
| 20 | Merimac Investments, Inc. | Fort Worth, TX 76109 | Oil & Gas Operator | Jan 1997 |
| 21 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 22 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 23 | Mills Oil & Gas | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 24 | Mingus Oil & Gas | Mingus, TX 76463 | Oil & Gas Operator | Oct 2025 |
| 25 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 26 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 27 | MJM Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 28 | MKS Consulting Corporation | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2005 |
| 29 | MKS Natural Gas Company | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2016 |
| 30 | Molsdorf Ag LLC | McAllen, TX 78503 | Oil Operator | Sep 2013 |
| 31 | Moncrief W A Jr | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2025 |
| 32 | Moncrief, C. B. | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2021 |
| 33 | Moore, Stephen Operating | Graham, TX 76450 | Oil & Gas Operator | Jun 2002 |
| 34 | Mosaic Oil LLC | Dallas, TX 75205 | Oil & Gas Operator | Oct 2025 |
| 35 | Mosaic Texas LLC | Dallas, TX 75205 | Oil & Gas Operator | Oct 2025 |
| 36 | Mote Resources, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2004 |
| 37 | Murjo Oil & Royalty Company | Fort Worth, TX 76121 | Oil & Gas Operator | Jun 2025 |
| 38 | Myers, A. J. | Jacksboro, TX 76458 | Oil & Gas Operator | Oct 2025 |