| 1 | M. K. Production | Caldwell, TX 77836 | Oil & Gas Operator | Mar 2008 |
| 2 | Magnolia Oil & Gas Operating LLC | Houston, TX 77046 | Oil & Gas Operator | Sep 2026 |
| 3 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Jun 2026 |
| 4 | Marlin Energy Resources, LLC | Lafayette, LA 70503 | Oil & Gas Operator | May 2018 |
| 5 | Marwell Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Apr 2006 |
| 6 | Mayjac I, LLC | Midland, TX 79705 | Oil & Gas Operator | Sep 2026 |
| 7 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 8 | McCool John E | Youngsville, PA 16371 | Oil & Gas Operator | Jun 2026 |
| 9 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Sep 2026 |
| 10 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 11 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 12 | Mescalero Energy, Inc. | San Antonio, TX 78231 | Oil & Gas Operator | Aug 2003 |
| 13 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 14 | Mid-Gulf, Inc. | Brenham, TX 77834 | Oil & Gas Operator | Mar 2008 |
| 15 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 16 | Mineral Technologies, Inc. | Midland, TX 79704 | Oil & Gas Operator | Sep 2026 |
| 17 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 18 | Mna Enterprises LTD. Co. | Hobbs, NM 88242 | Oil & Gas Operator | Jan 2026 |
| 19 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Dec 2007 |
| 20 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Feb 2026 |
| 21 | Mobile Production Systems, Inc. | Austin, TX 78711 | Oil & Gas Operator | Feb 1995 |
| 22 | Montclair Energy LLC | Edmond, OK 73034-7291 | Oil & Gas Operator | Jan 2026 |
| 23 | Moon Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Mar 2003 |
| 24 | Morris, W. Dale Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Sep 2026 |
| 25 | Morrow Resources, Inc. | San Angelo, TX 76904 | Oil & Gas Operator | Oct 2004 |
| 26 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Sep 2026 |
| 27 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |