| 1 | Magic Oil & Gas Inc. | Houston, TX 77079 | Oil & Gas Operator | Jan 2001 |
| 2 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 3 | Manti Exploration Operating LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2015 |
| 4 | Manti Operating Company | Covington, LA 70435 | Oil & Gas Operator | Oct 2025 |
| 5 | Mantle Oil & Gas, LLC | Friendswood, TX 77546 | Oil & Gas Operator | Oct 2025 |
| 6 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 7 | Matco Oil Co. | Saratoga, TX 77585 | Oil & Gas Operator | Apr 1999 |
| 8 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Aug 2025 |
| 9 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 10 | Meason Operating Company | Natchez, MS 39121 | Oil & Gas Operator | Dec 2011 |
| 11 | Medallion Oil Company | Houston, TX 77251 | Oil & Gas Operator | Jan 2012 |
| 12 | Mer Resources | Edmond, OK 73013 | Oil & Gas Operator | Oct 2025 |
| 13 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 14 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 15 | Milestone Operating, Inc. | Montgomery, TX 77316 | Oil & Gas Operator | Oct 2025 |
| 16 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 17 | Moon Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Mar 2003 |
| 18 | Moose Oil & Gas Co. | Houston, TX 77002 | Oil & Gas Operator | Feb 2000 |
| 19 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 20 | Mosman Operating, LLC | Dallas, TX 75204 | Oil Operator | Oct 2025 |
| 21 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 22 | Murphy Energy Services, LP | Saratoga, TX 77585 | Oil Operator | Dec 2018 |
| 23 | Murphy Exploration & Prod. Co. | Houston, TX 77094 | Oil & Gas Operator | Jun 2011 |
| 24 | Murphy Oil USA Inc | New Orleans, LA 70161 | Oil & Gas Operator | Jan 1993 |