| 1 | M & M Oil Co., LLC | Oil City, LA 71061 | Oil & Gas Operator | Dec 2024 |
| 2 | Machin & Associates, Inc. | Longview, TX 75606 | Oil & Gas Operator | Dec 2024 |
| 3 | Manziel Interests | Tyler, TX 75711 | Oil & Gas Operator | Jun 2004 |
| 4 | Manziel Management Corporation | Tyler, TX 75711 | Oil Operator | Feb 2014 |
| 5 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Nov 2024 |
| 6 | Marion County Prod. Co., L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2024 |
| 7 | Martineau Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | May 2024 |
| 8 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 9 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | Dec 2024 |
| 10 | McBrayer Oil Corporation | Rockport, TX 78381 | Oil & Gas Operator | Nov 1994 |
| 11 | McDonald Resources, LLC | Jefferson, TX 75657 | Oil & Gas Operator | Dec 2024 |
| 12 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 13 | McKnight, C. L. | McLeod, TX 75565 | Oil & Gas Operator | Dec 2024 |
| 14 | McKnight, C. L. Oil Co. LLP | McLeod, TX 75565 | Oil & Gas Operator | Dec 2024 |
| 15 | McKnight, J. C. | Jefferson, TX 75657 | Oil & Gas Operator | Nov 2019 |
| 16 | McRae Exploration & Prod., Inc. | Houston, TX 77064 | Oil & Gas Operator | Feb 2017 |
| 17 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | Dec 2024 |
| 18 | MHM Oil Co. | Dallas, TX 75240 | Oil & Gas Operator | Oct 2002 |
| 19 | MHM Pipeline Co., Inc. | Dallas, TX 75252 | Oil & Gas Operator | Dec 2024 |
| 20 | Mitchell Energy Company L.P. | Spring, TX 77387 | Oil & Gas Operator | Mar 2008 |
| 21 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 22 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 23 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Dec 2024 |
| 24 | Moransco Energy Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2024 |