| 1 | Mahan, Janet L | | Oil & Gas Operator | Nov 2025 |
| 2 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 3 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Dec 2025 |
| 4 | Maple Properties Corp | Dallas, TX 75204 | Oil & Gas Operator | Jan 1999 |
| 5 | Marathon Oil Company LLC | Houston, TX 77079 | Oil & Gas Operator | Dec 2025 |
| 6 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Nov 2025 |
| 7 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Nov 2025 |
| 8 | Marrakesh Oil Company | Oklahoma City, OK 73118 | Oil & Gas Operator | Jun 1995 |
| 9 | Marsh Operating Company | Dallas, TX 75221 | Oil & Gas Operator | Sep 2025 |
| 10 | Martin'S Resources LLC | Woodward, OK 73801-5641 | Oil & Gas Operator | Nov 2025 |
| 11 | Matador E & P Company Inc | | Oil & Gas Operator | May 2020 |
| 12 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Dec 2025 |
| 13 | McKenzie Petroleum Company | Houston, TX 77063 | Oil & Gas Operator | Aug 1995 |
| 14 | McKinney Operating Company | Canadian, TX 79014 | Gas Operator | May 2002 |
| 15 | McNic Oil & Gas Midcontinent | Oklahoma City, OK 73154-0526 | Oil & Gas Operator | May 2024 |
| 16 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Dec 2025 |
| 17 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 18 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 19 | Merex Resources, Inc. | Amarillo, TX 79159 | Oil & Gas Operator | Sep 2019 |
| 20 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Feb 2026 |
| 21 | Merrick Ward S Inc | Ardmore, OK 73402 | Oil & Gas Operator | Feb 2001 |
| 22 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 23 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Feb 2026 |
| 24 | Mid-Con Energy Operating, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | May 2020 |
| 25 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Dec 2025 |
| 26 | Middle Bay Production Co. Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2014 |
| 27 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 28 | Midwestern Exploration Company | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 29 | Mikco Inc | Tulsa, OK 74133 | Oil & Gas Operator | May 2001 |
| 30 | Montgomery Exploration Co LTD | Dallas, TX 75204-2634 | Oil & Gas Operator | Dec 2025 |
| 31 | Morrison International Energy Inc | Oklahoma City, OK 73189-0537 | Oil & Gas Operator | Feb 2025 |
| 32 | Muras Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | Nov 2025 |
| 33 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 34 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Dec 2025 |