| 1 | M. J. G., Inc. | Alice, TX 78333 | Oil & Gas Operator | Jul 2010 |
| 2 | Magic Circle Energy | Oklahoma City, OK 73185 | Oil & Gas Operator | Dec 1983 |
| 3 | Magnolia Oil & Gas Operating LLC | Houston, TX 77046 | Oil & Gas Operator | Dec 2024 |
| 4 | Magnum Engineering Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2024 |
| 5 | Magnum Operating, LLC | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2024 |
| 6 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 7 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2024 |
| 8 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 9 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 10 | Marathon Oil Ef LLC | Houston, TX 77024 | Oil & Gas Operator | Dec 2024 |
| 11 | Marmaton Oil Company | Houston, TX 77002 | Oil & Gas Operator | Jul 1998 |
| 12 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | Dec 2024 |
| 13 | Marwell Petroleum LTD Partnrship | Houston, TX 77027 | Oil & Gas Operator | Dec 2024 |
| 14 | Marwell Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Apr 2006 |
| 15 | Mascot Oil Company | Schulenburg, TX 78956 | Oil & Gas Operator | Dec 2024 |
| 16 | Mastodon Operating Company, LLC | Houston, TX 77027 | Oil & Gas Operator | Dec 2024 |
| 17 | Matador Production Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 18 | McCarter, A. Nelson | Houston, TX 77063 | Oil & Gas Operator | Aug 2003 |
| 19 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 20 | McRae Exploration & Prod., Inc. | Houston, TX 77064 | Oil & Gas Operator | Feb 2017 |
| 21 | Mego Resources, LLC | Taft, TX 78390 | Oil & Gas Operator | Dec 2024 |
| 22 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 23 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 24 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 25 | Messy Oil And Gas, LLC | Garwood, TX 77442 | Oil & Gas Operator | Dec 2024 |
| 26 | Mestena Operating, LTD. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jun 2009 |
| 27 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 28 | Midstates Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2024 |
| 29 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 30 | Miner, R. C. Inc. | Corpus Chrsti, TX 78413 | Oil & Gas Operator | Apr 2002 |
| 31 | Miner, R. C. Oil, Inc. | MC Queeney, TX 78123 | Oil & Gas Operator | Dec 2024 |
| 32 | Mission Resources Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2008 |
| 33 | Mission River Systems, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Dec 2024 |
| 34 | Modern Exploration, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Dec 2024 |
| 35 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 36 | Moose Oil & Gas Co. | Houston, TX 77002 | Oil & Gas Operator | Feb 2000 |
| 37 | Moose Operating Co., Inc. | Houston, TX 77006 | Oil & Gas Operator | Dec 2024 |
| 38 | Mosaic Oil LLC | Dallas, TX 75205 | Oil & Gas Operator | Dec 2024 |
| 39 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 40 | Mosley Oil &Gas Inc | Houston, TX 77002 | Oil & Gas Operator | Dec 2024 |
| 41 | Mueller Engineering Corp. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Feb 2002 |
| 42 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | Dec 2024 |
| 43 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2024 |