| 1 | M. E. Operating & Services, Inc. | Fort Worth, TX 76104 | Oil & Gas Operator | Mar 2025 |
| 2 | Mac Operating | Graham, TX 76450 | Oil & Gas Operator | Jun 2023 |
| 3 | Maddux Oil & Gas | Strawn, TX 76475 | Oil & Gas Operator | Mar 2025 |
| 4 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Jan 2025 |
| 5 | Mariah Energy Corp. | Austin, TX 78716 | Oil & Gas Operator | Apr 1999 |
| 6 | Marjac Oil Company, Inc. | Breckenridge, TX 76424 | Oil & Gas Operator | Mar 2025 |
| 7 | Martin Petroleum Corp. | Graham, TX 76450 | Oil & Gas Operator | Mar 2025 |
| 8 | Mash Oilfield Services, LP | Graham, TX 76450 | Oil & Gas Operator | Mar 2025 |
| 9 | Mayo, Eddie | Fredericksbrg, TX 78624 | Oil & Gas Operator | Mar 2025 |
| 10 | McClure, J.D. Trust | Denton, TX 76209 | Oil & Gas Operator | Mar 2025 |
| 11 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 12 | McCown Engineering | Wichita Falls, TX 76310 | Oil & Gas Operator | Mar 2025 |
| 13 | McCracken, H. L. Company | Wichita Falls, TX 76302 | Oil & Gas Operator | Mar 2025 |
| 14 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Mar 2025 |
| 15 | McKee, Kenneth W. Oil Co. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 16 | McKenzie Operating Company, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2011 |
| 17 | McMahon-Bullington Drilling Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Mar 1996 |
| 18 | McMahon-Bullington LP | Wichita Falls, TX 76307 | Oil & Gas Operator | Apr 2009 |
| 19 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Mar 2025 |
| 20 | Meeker & Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 21 | Melrose Operating Company | Dallas, TX 75201 | Oil & Gas Operator | Sep 2011 |
| 22 | Merenco | Midland, TX 79702 | Oil & Gas Operator | Dec 1996 |
| 23 | Merimac Investments, Inc. | Fort Worth, TX 76109 | Oil & Gas Operator | Jan 1997 |
| 24 | Merrimac Energy Corp. | Dallas, TX 75206 | Oil & Gas Operator | Aug 1999 |
| 25 | Mid-Continent Energy, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2020 |
| 26 | Miller Operating Company LLC | Lafayette, LA 70598 | Oil & Gas Operator | Mar 2025 |
| 27 | Mills Oil & Gas | Jacksboro, TX 76458 | Oil & Gas Operator | Mar 2008 |
| 28 | Mills, H. E. | Lipan, TX 76462 | Oil & Gas Operator | Sep 2004 |
| 29 | Mingus Oil & Gas | Mingus, TX 76463 | Oil & Gas Operator | Mar 2025 |
| 30 | Minton Oil & Gas Properties | Graford, TX 76449 | Gas Operator | Mar 2025 |
| 31 | Minuteman Energy, LLC | Georgetown, TX 78633 | Oil & Gas Operator | Feb 2015 |
| 32 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 33 | MKS Consulting Corporation | Weatherford, TX 76086 | Oil & Gas Operator | Jul 2005 |
| 34 | MKS Natural Gas Company | Weatherford, TX 76086 | Oil & Gas Operator | Mar 2016 |
| 35 | Mna Enterprises LTD. Co. | Hobbs, NM 88242 | Oil & Gas Operator | Mar 2025 |
| 36 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 37 | Mogul Resources, LLC | Ranger, TX 76470 | Oil & Gas Operator | Mar 2025 |
| 38 | Mole Hole Prod. | Bridgeport, TX 76426 | Oil Operator | Mar 2025 |
| 39 | Momentum Operating Co., Inc. | Albany, TX 76430 | Oil & Gas Operator | Mar 2025 |
| 40 | Mont-Land Co. | Graham, TX 76450 | Oil & Gas Operator | Mar 2008 |
| 41 | Moore, Miles Inc. | Moran, TX 76464 | Oil & Gas Operator | Mar 2025 |
| 42 | Moore, Stephen Operating | Graham, TX 76450 | Oil & Gas Operator | Jun 2002 |
| 43 | Mosaic Oil LLC | Dallas, TX 75205 | Oil & Gas Operator | Mar 2025 |
| 44 | Mosaic Texas LLC | Dallas, TX 75205 | Oil & Gas Operator | Mar 2025 |
| 45 | MWS Producing, Inc. | Stanton, TX 79782 | Oil & Gas Operator | Mar 2025 |