| 1 | M & R Exploration Company | Houston, TX 77074 | Oil & Gas Operator | Aug 2003 |
| 2 | Magnum Engineering Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 3 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 4 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 5 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 6 | Marlin Energy Southwest GP, LLC | Lafayette, LA 70503 | Oil & Gas Operator | Oct 2025 |
| 7 | Masters Oil & Gas, LLC | Houston, TX 77079 | Oil & Gas Operator | Oct 2025 |
| 8 | Masters Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2008 |
| 9 | Maverick Drilling Co., Inc. | Austin, TX 78729 | Oil & Gas Operator | Mar 2015 |
| 10 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Jul 2025 |
| 11 | McCarter, A. Nelson | Houston, TX 77063 | Oil & Gas Operator | Aug 2003 |
| 12 | McGowan Working Partners | Jackson, MS 39296 | Oil & Gas Operator | Dec 2000 |
| 13 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | Oct 2025 |
| 14 | McGowen Resources Co., Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2003 |
| 15 | Meridian Resource & Expl LLC,The | Houston, TX 77094 | Oil & Gas Operator | Nov 2012 |
| 16 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 17 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 18 | Middleton Oil Company | Houston, TX 77006 | Oil & Gas Operator | Oct 2025 |
| 19 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 20 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 21 | Miller, Bob I. | Abilene, TX 79604 | Oil & Gas Operator | Mar 2008 |
| 22 | Minexprod LLC | Katy, TX 77494 | Oil Operator | Oct 2025 |
| 23 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 24 | MJ Oil, Inc. | Houston, TX 77265 | Oil & Gas Operator | Oct 2025 |
| 25 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 26 | Mortimer Exploration Company | San Antonio, TX 78209 | Oil & Gas Operator | Sep 2003 |
| 27 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 28 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 29 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |