| 1 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | Apr 2024 |
| 2 | Machin & Associates, Inc. | Longview, TX 75606 | Oil & Gas Operator | Apr 2024 |
| 3 | Magnolia Production Co | Atlanta, TX 75551 | Oil & Gas Operator | Apr 2024 |
| 4 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Feb 2024 |
| 5 | Marion County Prod. Co., L.L.C. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2024 |
| 6 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 7 | McBee Company, The | Dallas, TX 75219 | Oil & Gas Operator | Dec 1997 |
| 8 | McBee Operating Company, L.L.C. | Dallas, TX 75209 | Oil & Gas Operator | Apr 2024 |
| 9 | McCormick Production Co, Inc. | Oil City, LA 71061 | Oil & Gas Operator | Apr 2024 |
| 10 | McDonald Resources, LLC | Jefferson, TX 75657 | Oil & Gas Operator | Apr 2024 |
| 11 | McKnight, C. L. | McLeod, TX 75565 | Oil & Gas Operator | Apr 2024 |
| 12 | McKnight, C. L. Oil Co. LLP | McLeod, TX 75565 | Oil & Gas Operator | Apr 2024 |
| 13 | McKnight, J. C. | Jefferson, TX 75657 | Oil & Gas Operator | Nov 2019 |
| 14 | Midstates Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Apr 2024 |
| 15 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 16 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2024 |
| 17 | Moransco Energy Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2024 |
| 18 | Murphy Oil USA Inc | New Orleans, LA 70161 | Oil & Gas Operator | Jan 1993 |
| 19 | Mustang Energy Inc. | Porter, TX 77365 | Oil & Gas Operator | Mar 2008 |
| 20 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |