| 1 | M W Production Co. | New Braunfels, TX 78130 | Oil & Gas Operator | Aug 2003 |
| 2 | M. K. Production | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2008 |
| 3 | Magna Oil & Gas Corporation | Irving, TX 75017 | Oil & Gas Operator | Feb 2016 |
| 4 | Magnolia Oil & Gas Operating LLC | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 5 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 6 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 7 | Mai Oil Operations, Inc. | Dallas, TX 75225 | Oil & Gas Operator | Jun 2025 |
| 8 | Majestic Petroleum Corporation | Dallas, TX 75230 | Oil & Gas Operator | Oct 1996 |
| 9 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 10 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 11 | Matrix Petroleum, LLC | Houston, TX 77077 | Oil & Gas Operator | Oct 2025 |
| 12 | Maverick Prod. Co., Inc. | Houston, TX 77056 | Oil & Gas Operator | Oct 2025 |
| 13 | MBR Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2025 |
| 14 | McCarthy Oil & Gas Corporation | Houston, TX 77056 | Oil & Gas Operator | Oct 2007 |
| 15 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 16 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 17 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 18 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 19 | Melton, Joe, DRLG. Co., Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 20 | Micro Operating, Inc. | Bryan, TX 77807 | Oil & Gas Operator | Oct 2025 |
| 21 | Mid Continent Resources, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2025 |
| 22 | Mineral Technologies, Inc. | Midland, TX 79704 | Oil & Gas Operator | Oct 2025 |
| 23 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 24 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 25 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 26 | Modern Exploration, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Oct 2025 |
| 27 | Morris, W. Dale Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Oct 2025 |
| 28 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 29 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |