| 1 | Mahfouz Energy Company | Houston, TX 77255 | Oil & Gas Operator | Nov 2020 |
| 2 | Marcon Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | Oct 2011 |
| 3 | Marrow, N. S. | Austin, TX 78703 | Oil & Gas Operator | Aug 2012 |
| 4 | Martex Oil & Gas, Inc. | Estes Park, CO 80517 | Oil & Gas Operator | Sep 2026 |
| 5 | Maxey & Swan Oil Co. | Decatur, TX 76234 | Oil & Gas Operator | Apr 2007 |
| 6 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 7 | McClymond, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Jul 2001 |
| 8 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 9 | McCommons Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2026 |
| 10 | McCurdy Oil Co. | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2025 |
| 11 | McCutchin Petroleum Corporation | Dallas, TX 75225 | Oil & Gas Operator | Sep 2026 |
| 12 | McCutchin, Jerry | Dallas, TX 75380 | Oil & Gas Operator | Mar 2008 |
| 13 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 14 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 15 | McGuire Brothers | Phoenix, AZ 85045 | Oil & Gas Operator | Sep 2026 |
| 16 | MDM Energy, Inc. | The Colony, TX 75056 | Oil & Gas Operator | Sep 2026 |
| 17 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 18 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 19 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Sep 2026 |
| 20 | Merritt Operating, Inc. | Mineola, TX 75773 | Oil & Gas Operator | Sep 2026 |
| 21 | Messy Oil And Gas, LLC | Garwood, TX 77442 | Oil & Gas Operator | Sep 2026 |
| 22 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 23 | Mid Texas Natural Gas | Kyle, TX 78640 | Oil & Gas Operator | May 2019 |
| 24 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 25 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 26 | Miles Production Co. | Argyle, TX 76226 | Oil & Gas Operator | Mar 2008 |
| 27 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 28 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 29 | MKS Consulting Corporation | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2005 |
| 30 | MKS Natural Gas Company | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2016 |
| 31 | Mobil Petro Vac, Inc. | Duncan, OK 73533 | Oil & Gas Operator | Sep 2026 |
| 32 | Monitor O&G, L.L.C. | Frisco, TX 75034 | Oil & Gas Operator | Jan 2016 |
| 33 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 34 | Moody Oil Co. | Pearsall, TX 78061 | Oil & Gas Operator | Sep 2026 |
| 35 | Moriah Resources, Inc. | Midland, TX 79704 | Oil & Gas Operator | Mar 2008 |
| 36 | Mote Resources, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Dec 2004 |
| 37 | Murjo Oil & Royalty Company | Fort Worth, TX 76121 | Oil & Gas Operator | Dec 2019 |
| 38 | Myers, A. J. | Jacksboro, TX 76458 | Oil & Gas Operator | Sep 2026 |
| 39 | Myung And Associates, Inc. | Houston, TX 77056 | Oil & Gas Operator | May 2000 |