| 1 | M & M Construction Co. | Kilgore, TX 75663 | Oil & Gas Operator | Jan 1996 |
| 2 | M A S Operators | Kilgore, TX 75663 | Oil & Gas Operator | Jul 1999 |
| 3 | M-C Production & Drilling Co,Inc | Longview, TX 75608 | Oil & Gas Operator | Sep 2025 |
| 4 | Machin & Associates, Inc. | Longview, TX 75606 | Oil & Gas Operator | Sep 2025 |
| 5 | Magnolia Production Co | Atlanta, TX 75551 | Oil & Gas Operator | Sep 2025 |
| 6 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Jul 2025 |
| 7 | Martineau Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Jan 2025 |
| 8 | Mass Energy, Inc | Houston, TX 77056 | Oil & Gas Operator | Mar 2008 |
| 9 | Maxima Energy Corp. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2012 |
| 10 | Maximus Operating, LTD. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2025 |
| 11 | McBee Operating Company, L.L.C. | Dallas, TX 75209 | Oil & Gas Operator | Sep 2025 |
| 12 | McBrayer Oil Corporation | Rockport, TX 78381 | Oil & Gas Operator | Nov 1994 |
| 13 | McCutchin, Gene | Dallas, TX 75380 | Oil & Gas Operator | Aug 2003 |
| 14 | McCutchin, Jerry | Dallas, TX 75380 | Oil & Gas Operator | Mar 2008 |
| 15 | McDonald Production | Lubbock, TX 79408 | Oil & Gas Operator | Mar 2003 |
| 16 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 17 | Meadows Oil Company | Plano, TX 75075 | Oil & Gas Operator | Aug 2004 |
| 18 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Sep 2025 |
| 19 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 20 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 21 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Sep 2025 |
| 22 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 23 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 24 | Miken Oil, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Sep 2025 |
| 25 | Miller Energy Inc | Houston, TX 77024 | Oil & Gas Operator | Oct 2016 |
| 26 | Miller, R. A. Energy, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2003 |
| 27 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 28 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Sep 2025 |
| 29 | Moncrief W A Jr | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2025 |
| 30 | Montex Drilling Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2025 |
| 31 | Moon Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Mar 2003 |
| 32 | Moss Petroleum Company | Dallas, TX 75207 | Oil & Gas Operator | Sep 2025 |
| 33 | Muras Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 34 | Murphy Exploration & Prod. Co. | Houston, TX 77094 | Oil & Gas Operator | Jun 2011 |
| 35 | Murphy Exploration & Production | Houston, TX 77024 | Oil Operator | Dec 2024 |
| 36 | Murphy Oil USA Inc | New Orleans, LA 70161 | Oil & Gas Operator | Jan 1993 |
| 37 | Mustang Drilling, Inc. | Henderson, TX 75653 | Oil & Gas Operator | Aug 2024 |
| 38 | Mustang Drilling, LTD. | Henderson, TX 75653 | Oil & Gas Operator | May 2008 |
| 39 | Mustang Operating Company | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2006 |