| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | M G U Development Co | Oil & Gas Operator | Jun 1987 | |
| 2 | M G U Development Co And Mask Thomas B And Ma020 | Oil & Gas Operator | Jun 1987 | |
| 3 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Feb 2026 |
| 4 | Mask Thomas B | Oil & Gas Operator | Jul 1991 | |
| 5 | Mask Thomas B And Markel Ray D And Wood K P | Oil & Gas Operator | Aug 1986 | |
| 6 | Mask Thomas B And Patrick Petroleum Corp | Oil & Gas Operator | Jun 1992 | |
| 7 | Maskeny Edward D | Oil & Gas Operator | Jun 1998 | |
| 8 | Matrix Exploration And Development LLC | Oil & Gas Operator | Oct 2008 | |
| 9 | McConnell And Scully Inc | Oil & Gas Operator | Feb 2026 | |
| 10 | Meridian Resources LLC | Evansville, IN 47715 | Oil Operator | Jul 2024 |
| 11 | Michigan Gas Utilities Co | Oil & Gas Operator | Mar 2011 | |
| 12 | Michigan Geosearch Inc | Lansing, MI 48917 | Oil & Gas Operator | Jan 2026 |
| 13 | Miller Energy Company II LLC | Oil & Gas Operator | Feb 2026 | |
| 14 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2026 |
| 15 | Mutch Harry L | Oil & Gas Operator | Oct 1991 | |
| 16 | Mutch J O | Gas Operator | Mar 1990 |