| 1 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Mar 2025 |
| 2 | M-C Production & Drilling Co,Inc | Longview, TX 75608 | Oil & Gas Operator | Mar 2025 |
| 3 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | Mar 2025 |
| 4 | Machin & Associates, Inc. | Longview, TX 75606 | Oil & Gas Operator | Mar 2025 |
| 5 | Magnolia Production Co | Atlanta, TX 75551 | Oil & Gas Operator | Mar 2025 |
| 6 | Manziel Management Corporation | Tyler, TX 75711 | Oil Operator | Feb 2014 |
| 7 | Mar-Bec Energy Company, L.L.C. | Shreveport, LA 71105 | Oil & Gas Operator | May 2001 |
| 8 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Jan 2025 |
| 9 | Maroon Energy LLC | Spring, TX 77379 | Oil & Gas Operator | Mar 2025 |
| 10 | Marquee Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2025 |
| 11 | Marshall, Sam | Granbury, TX 76048 | Oil & Gas Operator | Aug 2010 |
| 12 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 13 | Matador Production Company | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 14 | Maximus Operating, LTD. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2025 |
| 15 | Maxum Energy Corp | Plano, TX 75025 | Oil & Gas Operator | Jan 2003 |
| 16 | McBee Company, The | Dallas, TX 75219 | Oil & Gas Operator | Dec 1997 |
| 17 | McBride Operating LLC | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2025 |
| 18 | McBride, Jerrel L Enterprise Inc | Kilgore, TX 75663 | Oil & Gas Operator | Jun 1999 |
| 19 | McCulliss Resources Co Inc | Littleton, CO 80161-3248 | Oil & Gas Operator | Jun 2009 |
| 20 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Mar 2025 |
| 21 | McDonnold Operating, Inc. | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 22 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 23 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 24 | Mercury Operating, LLC | Dallas, TX 75208 | Oil & Gas Operator | Mar 2025 |
| 25 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 26 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | Jan 2025 |
| 27 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 28 | MHM Oil Co. | Dallas, TX 75240 | Oil & Gas Operator | Oct 2002 |
| 29 | Midcoast G & P (East Texas) L.P. | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 30 | Millennium Minerals Corporation | Fredericksbrg, TX 78624 | Oil Operator | Mar 2025 |
| 31 | Miller, R. A. Energy, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2003 |
| 32 | MJ Energy Company, LLC | Kilgore, TX 75663 | Oil Operator | Mar 2025 |
| 33 | MMGL East Texas III, LLC | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 34 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 35 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Mar 2025 |
| 36 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 37 | Moon Operating, Inc. | Longview, TX 75601 | Oil & Gas Operator | Mar 2003 |
| 38 | Moransco Energy Corporation | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2025 |
| 39 | Morris, W. Dale Inc. | Mineral Wells, TX 76068 | Oil & Gas Operator | Mar 2025 |
| 40 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Mar 2025 |
| 41 | Munoco Co. | El Dorado, AR 71730 | Oil & Gas Operator | Jul 2021 |
| 42 | Murjo Oil & Royalty Company | Fort Worth, TX 76121 | Oil & Gas Operator | Nov 2024 |
| 43 | Murphy Exploration & Production | Houston, TX 77024 | Oil Operator | Oct 2024 |
| 44 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |