| 1 | M & M Resources Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2018 |
| 2 | M M Energy Inc | Oklahoma City, OK 73156 | Oil & Gas Operator | Oct 2025 |
| 3 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Dec 2025 |
| 4 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Oct 2025 |
| 5 | Mack Oil Company | Duncan, OK 73534 | Oil & Gas Operator | Nov 2000 |
| 6 | Marathon Oil Company LLC | Houston, TX 77079 | Oil & Gas Operator | Oct 2025 |
| 7 | Maxim Energy Corporation | Baytown, TX 77520 | Oil & Gas Operator | Oct 2025 |
| 8 | McCool John E | Youngsville, PA 16371 | Oil & Gas Operator | Sep 2025 |
| 9 | McMillin C C & Company Inc | Guthrie, OK 73044 | Oil & Gas Operator | Sep 2025 |
| 10 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Oct 2025 |
| 11 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 12 | Megaenergy Operating, Inc. | Edmond, OK 73034 | Oil & Gas Operator | Jul 2015 |
| 13 | Mel-Ray Oil Company | Nowata, OK 74048-0149 | Oil & Gas Operator | Mar 2004 |
| 14 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 15 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 16 | Middle Bay Production Co. Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2014 |
| 17 | Min-Tex Oil Corporation | Tulsa, OK 74170 | Oil & Gas Operator | Dec 1996 |
| 18 | Mobil Exp & Prod Us Inc | Houston, TX 77060-1991 | Oil & Gas Operator | May 2001 |
| 19 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Oct 2025 |
| 20 | Moore Clay | Bradenton, FL 34211 | Oil & Gas Operator | Sep 2025 |
| 21 | Moran-K Oil LLC | Seminole, OK 74868 | Oil & Gas Operator | Oct 2025 |
| 22 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Dec 2025 |
| 23 | Muegge Don E | Lamont, OK 74643-5010 | Oil & Gas Operator | Dec 1996 |
| 24 | Muras Energy Inc | Edmond, OK 73013 | Oil & Gas Operator | Oct 2025 |
| 25 | Musgrove Energy Inc | Ponca City, OK 74602 | Oil & Gas Operator | Feb 2025 |
| 26 | Mustang Gas Products LLC | Oklahoma City, OK 73114-7406 | Oil & Gas Operator | Sep 2022 |