| 1 | M IV Ops., Inc. | San Antonio, TX 78217 | Oil & Gas Operator | Mar 1998 |
| 2 | M-G Gas Company, Inc. | Plano, TX 75086 | Oil & Gas Operator | Jun 1999 |
| 3 | M. J. G., Inc. | Alice, TX 78333 | Oil & Gas Operator | Jul 2010 |
| 4 | Magna Oil & Gas Corporation | Irving, TX 75017 | Oil & Gas Operator | Feb 2016 |
| 5 | Magnum Engineering Company | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Oct 2025 |
| 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 | Oct 2025 |
| 8 | Marathon Oil Ef LLC | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 9 | Mark IV Energy | San Antonio, TX 78213 | Oil & Gas Operator | Apr 1993 |
| 10 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 11 | Marshfield Oil & Gas, LLC | Houston, TX 77070 | Oil & Gas Operator | Oct 2025 |
| 12 | Marwell Petroleum LTD Partnrship | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 13 | Marwell Petroleum, Inc. | Houston, TX 77057 | Oil & Gas Operator | Apr 2006 |
| 14 | MB Energy, LLC | San Antonio, TX 78233 | Oil & Gas Operator | Oct 2025 |
| 15 | McCombs Energy LLC | Houston, TX 77056 | Oil & Gas Operator | Jan 2006 |
| 16 | McCombs Energy, LTD. | Houston, TX 77056 | Oil & Gas Operator | Aug 2017 |
| 17 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 18 | McFarland Energy, Inc. | New Orleans, LA 70160 | Oil & Gas Operator | Dec 2009 |
| 19 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | Oct 2025 |
| 20 | McGuffin, Joe S. Inc. | Mathis, TX 78368 | Gas Operator | Oct 2025 |
| 21 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 22 | McMahon Operating Co., L.C. | Pampa, TX 79066 | Oil & Gas Operator | Dec 2004 |
| 23 | McRae Exploration & Prod., Inc. | Houston, TX 77064 | Oil & Gas Operator | Feb 2017 |
| 24 | Mego Resources, LLC | Taft, TX 78390 | Oil & Gas Operator | Oct 2025 |
| 25 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 26 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 27 | Messy Oil And Gas, LLC | Garwood, TX 77442 | Oil & Gas Operator | Oct 2025 |
| 28 | Metano Energy, LP | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2008 |
| 29 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 30 | Michael Petroleum Corporation | Houston, TX 77040 | Oil & Gas Operator | Dec 2001 |
| 31 | Midas Resources, Inc. | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Oct 2025 |
| 32 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 33 | Midstates Corporation | San Antonio, TX 78217 | Oil & Gas Operator | Oct 2025 |
| 34 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 35 | Mina Energy, Inc. | Boerne, TX 78006 | Oil & Gas Operator | Feb 2012 |
| 36 | Miramar Petroleum, Inc. | Corpus Chrsti, TX 78463 | Oil & Gas Operator | Sep 2017 |
| 37 | Mission River Systems, Inc. | Corpus Chrsti, TX 78473 | Oil & Gas Operator | Oct 2025 |
| 38 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 39 | Mna Enterprises LTD. Co. | Hobbs, NM 88242 | Oil & Gas Operator | Jul 2025 |
| 40 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 41 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 42 | Modern Exploration, Inc. | Sherman, TX 75090 | Oil & Gas Operator | Oct 2025 |
| 43 | Mohican Oil & Gas, L.L.C. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Apr 2013 |
| 44 | Mohican Operating, L.L.C. | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Apr 2021 |
| 45 | Mooringsport Energy Prod. Co. | Shreveport, LA 71162 | Oil & Gas Operator | Oct 2025 |
| 46 | Morgan Enterprises, Inc. | Houston, TX 77024 | Oil & Gas Operator | Oct 2025 |
| 47 | Mortimer Production Company | San Antonio, TX 78209 | Oil & Gas Operator | Oct 2025 |
| 48 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 49 | Moy, Gary | Falls City, TX 78113 | Oil & Gas Operator | Nov 1998 |
| 50 | Mueller Engineering Corp. | Corpus Chrsti, TX 78476 | Oil & Gas Operator | Feb 2002 |
| 51 | Mueller Exploration, Inc. | Portland, TX 78374 | Oil & Gas Operator | Oct 2025 |
| 52 | Murphy Exploration & Production | Houston, TX 77024 | Oil Operator | Jan 2025 |