| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Manti Exploration Operating LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2015 |
| 2 | Marben Corporation | Oil Operator | Jul 1995 | |
| 3 | Martin Exploration Co. | Oil & Gas Operator | Apr 1986 | |
| 4 | Masters Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2008 |
| 5 | Maynard Oil Co. | Denver, CO 80202 | Oil & Gas Operator | Sep 2004 |
| 6 | McLain J. Forman | Oil & Gas Operator | Mar 1988 | |
| 7 | Memaca Petroleum Corporation | Oil & Gas Operator | Jan 1990 | |
| 8 | Merritt Operating, Inc. | Mineola, TX 75773 | Oil & Gas Operator | Dec 2025 |
| 9 | Metairie Energy Company, Inc. | Oil & Gas Operator | Nov 2019 | |
| 10 | Minden Oil & Gas, Inc. | Oil & Gas Operator | May 1985 | |
| 11 | Mobil E&P North America Inc. | Oil & Gas Operator | Jan 1994 | |
| 12 | Mobil Oil E & P Southeast Inc | Oil & Gas Operator | Sep 2013 | |
| 13 | Monterey Pipeline Co. | Oil Operator | Aug 1993 | |
| 14 | Mullins & Prichard | Oil & Gas Operator | May 1992 | |
| 15 | Murexco Petroleum Inc | Dallas, TX 75251 | Oil & Gas Operator | Oct 1996 |