| 1 | M & A Oil Company, LTD. | Wichita Falls, TX 76307 | Oil & Gas Operator | Oct 2025 |
| 2 | M.R.M. Operating, Inc. | Midland, TX 79707 | Oil & Gas Operator | Aug 2003 |
| 3 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 4 | Maralo, Inc. | Midland, TX 79702 | Oil & Gas Operator | Dec 1998 |
| 5 | Maralo, LLC | Midland, TX 79702 | Oil & Gas Operator | Mar 2008 |
| 6 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 7 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | Aug 2025 |
| 8 | Marwell Petroleum LTD Partnrship | Houston, TX 77027 | Oil & Gas Operator | Oct 2025 |
| 9 | MBR Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2025 |
| 10 | McBee Company, The | Dallas, TX 75219 | Oil & Gas Operator | Dec 1997 |
| 11 | McCann Corporation | Midland, TX 79710 | Oil & Gas Operator | Oct 2025 |
| 12 | McClymond, LTD. | Breckenridge, TX 76424 | Oil & Gas Operator | Dec 2009 |
| 13 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 14 | McShane, J. Inc. | Midland, TX 79702 | Oil & Gas Operator | Apr 2004 |
| 15 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 16 | Melton, Joe, DRLG. Co., Inc. | Midland, TX 79704 | Oil & Gas Operator | Dec 2004 |
| 17 | Mercury Exploration Co | Fort Worth, TX 76104 | Oil & Gas Operator | Dec 2006 |
| 18 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 19 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 20 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | Aug 2025 |
| 21 | Mesquite Oil & Gas Production | Breckenridge, TX 76424 | Oil & Gas Operator | Oct 2025 |
| 22 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Oct 2025 |
| 23 | MGF Oil Corporation | Tulsa, OK 74121 | Oil & Gas Operator | Jun 1998 |
| 24 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2025 |
| 25 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 26 | Mokan Capital, LLC | Spicewood, TX 78669 | Oil Operator | Oct 2025 |
| 27 | Moncrief W A Jr | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2025 |
| 28 | Mulloy, J. W. Associates, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jan 2003 |
| 29 | Munn, W. H. Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2002 |
| 30 | Murchison Oil & Gas Inc | Plano, TX 75024 | Oil & Gas Operator | May 2024 |
| 31 | MWL Energy LLC | Hamlin, TX 79520 | Oil Operator | Oct 2025 |
| 32 | Myd, Inc. | Irving, TX 75062 | Oil & Gas Operator | Mar 1998 |