| 1 | M W Production Co. | New Braunfels, TX 78130 | Oil & Gas Operator | Aug 2003 |
| 2 | M. S. Productions, Inc. | Pittsburg, KS 66762 | Oil & Gas Operator | Nov 2019 |
| 3 | Magnolia Oil & Gas Operating LLC | Houston, TX 77046 | Oil & Gas Operator | Dec 2024 |
| 4 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2024 |
| 5 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Oct 2024 |
| 6 | Market Street Energy, Inc. | Flatonia, TX 78941 | Oil & Gas Operator | Dec 2024 |
| 7 | Martineau Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | May 2024 |
| 8 | Matrix Petroleum, LLC | Houston, TX 77077 | Oil & Gas Operator | Dec 2024 |
| 9 | MBC Operating Co., Inc. | Garland, TX 75042 | Oil & Gas Operator | Aug 1993 |
| 10 | McA Petroleum Corporation | Flatonia, TX 78941 | Oil & Gas Operator | Dec 2024 |
| 11 | McCarter, A. Nelson | Houston, TX 77063 | Oil & Gas Operator | Aug 2003 |
| 12 | McCombs Energy LLC | Houston, TX 77056 | Oil & Gas Operator | Jan 2006 |
| 13 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Dec 2024 |
| 14 | Melton, Joe, DRLG. Co., Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 15 | Merica Oil Operating Company | Frisco, TX 75034 | Oil & Gas Operator | Sep 2024 |
| 16 | Mescalero Energy, Inc. | San Antonio, TX 78231 | Oil & Gas Operator | Aug 2003 |
| 17 | Mid-Gulf, Inc. | Brenham, TX 77834 | Oil & Gas Operator | Mar 2008 |
| 18 | Middle Bay Production Co. Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2014 |
| 19 | Mineral Development, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1996 |
| 20 | Mineral Technologies, Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2024 |
| 21 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 22 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 23 | ML Resources, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Mar 2008 |
| 24 | Mockingbird Oil, Inc. (I) | Spring, TX 77389 | Oil & Gas Operator | Dec 2024 |
| 25 | Morris, W. Dale Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Dec 2024 |
| 26 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Dec 2024 |
| 27 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | Dec 2024 |
| 28 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |