| 1 | M E Klein & Associates, Inc. | Norman, OK 73070 | Oil & Gas Operator | Jun 2025 |
| 2 | Mac 5 Operating, LLC | Pampa, TX 79065 | Oil & Gas Operator | Feb 2021 |
| 3 | Mace, T. A. | Oklahoma City, OK 73127 | Oil & Gas Operator | Feb 2008 |
| 4 | Magnum Hunter Production, Inc. | Irving, TX 75014 | Oil & Gas Operator | Dec 2019 |
| 5 | Makar Production Company | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 6 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 7 | Manti Operating Company | Covington, LA 70435 | Oil & Gas Operator | Oct 2025 |
| 8 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 9 | Maverick Brothers Operating,Inc. | Enid, OK 73702 | Oil & Gas Operator | Jun 2025 |
| 10 | Maxus Exploration Company | Dallas, TX 75201 | Oil & Gas Operator | Jan 1995 |
| 11 | Maxwell Resources Corporation | Oklahoma City, OK 73116-7746 | Oil & Gas Operator | Apr 2009 |
| 12 | McClure Oil Company, Inc. | Midland, TX 79701 | Oil & Gas Operator | Oct 2025 |
| 13 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 14 | McGee, Tom Corporation | Booker, TX 79005 | Oil & Gas Operator | Jun 2025 |
| 15 | McKinney Operating Company | Canadian, TX 79014 | Gas Operator | May 2002 |
| 16 | McNic Oil & Gas Midcontinent,Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 1999 |
| 17 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 18 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 19 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 20 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 21 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Oct 2025 |
| 22 | MFP Petroleum LTD. Partnership | Oklahoma City, OK 73142 | Oil & Gas Operator | Nov 2017 |
| 23 | Mge Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Jun 2025 |
| 24 | Mid-Continent Energy Operating Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 25 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 26 | Midstates Petroleum Company LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 27 | Midway Operating Company, L.L.C. | Woodward, OK 73802 | Oil & Gas Operator | Oct 2025 |
| 28 | Midwestern Exploration Co. | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 29 | Miltex Oil Company | Boerne, TX 78006 | Oil & Gas Operator | Oct 2025 |
| 30 | Mitchell Ehrlich Oil & Gas, LLC | Austin, TX 78746 | Oil & Gas Operator | Oct 2025 |
| 31 | MJM Oil & Gas, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Aug 2003 |
| 32 | Mobeetie Resource Dev LLC | Perryton, TX 79070 | Oil & Gas Operator | Oct 2025 |
| 33 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 34 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 35 | Mon Corp. | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |
| 36 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 37 | Moody Oil Co. | Pearsall, TX 78061 | Oil & Gas Operator | Oct 2025 |
| 38 | MRR Oil Inc. | Perryton, TX 79070 | Oil & Gas Operator | Jun 2002 |
| 39 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 40 | Myriad Resources Corporation | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |