| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | M-3 Industries | Casper, WY 82602 | Oil & Gas Operator | Jun 2025 |
| 2 | Mapco Oil Company | Oil & Gas Operator | Jan 1985 | |
| 3 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 4 | McCulliss Resource Company Inc | Denver, CO 80202 | Oil & Gas Operator | Jun 1999 |
| 5 | McMurry Oil LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 6 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 7 | Merit Productions | Oil Operator | Sep 1996 | |
| 8 | Michigan-Wisconsin Pipe Line Co | Oil & Gas Operator | Dec 1983 | |
| 9 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |