| 1 | Maddox Energy Corporation | Dallas, TX BAD ADDR | Oil & Gas Operator | Jul 1995 |
| 2 | Magnum Minerals, Inc. | | Oil & Gas Operator | May 1998 |
| 3 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 4 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 5 | Manti Exploration Operating LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2015 |
| 6 | Manti Operating Company | Covington, LA 70435 | Oil & Gas Operator | Oct 2025 |
| 7 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 8 | Marion Corporation | | Oil & Gas Operator | Jan 2001 |
| 9 | Maritech Resources, LLC | | Oil & Gas Operator | May 2011 |
| 10 | Marks Operating LLC | | Oil & Gas Operator | Jul 2016 |
| 11 | Marlin Energy Offshore, L.L.C. | | Oil & Gas Operator | Jun 2006 |
| 12 | Marquis Resources, LLC | | Oil & Gas Operator | Jul 2021 |
| 13 | Marshall Exploration, Inc. | | Oil & Gas Operator | Jun 1992 |
| 14 | Martin Energy LLC | | Oil & Gas Operator | Apr 2023 |
| 15 | Martin Exploration Co. | | Oil & Gas Operator | Apr 1986 |
| 16 | Martin-Marks Operating Co. LLC | | Oil & Gas Operator | Dec 2010 |
| 17 | Masters Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2008 |
| 18 | Matrix Oil & Gas, Inc. | | Oil & Gas Operator | Jul 2001 |
| 19 | May Petroleum, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 20 | McAlester Fuel Co | Houston, TX 77042 | Oil & Gas Operator | Jan 2010 |
| 21 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 22 | McGowan Working Partners | Jackson, MS 39296 | Oil & Gas Operator | Dec 2000 |
| 23 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | Oct 2025 |
| 24 | McMoran Exploration Company | | Oil & Gas Operator | May 1985 |
| 25 | McMoran Oil & Gas LLC | New Orleans, LA 70160 | Oil & Gas Operator | Oct 2021 |
| 26 | McMoran Production Co. | | Oil & Gas Operator | May 1985 |
| 27 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 28 | Mesa Gulf Coast LLC | | Oil & Gas Operator | Dec 2020 |
| 29 | Micron Minerals Company | | Oil & Gas Operator | Sep 1988 |
| 30 | Mid Louisiana Gas Company | | Oil & Gas Operator | Oct 2002 |
| 31 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 32 | Mobil Oil E & P Southeast Inc | | Oil & Gas Operator | Sep 2013 |
| 33 | Moore McCormack Energy, Inc. | | Oil & Gas Operator | Jul 1988 |
| 34 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 35 | Mullins & Prichard | | Oil & Gas Operator | May 1992 |