| 1 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Oct 2024 |
| 2 | Marion Corporation | | Oil & Gas Operator | Jan 2001 |
| 3 | Marjo Operating Mid-Continent LLC | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2024 |
| 4 | Meade Energy Corporation | Oklahoma City, OK 73118-4015 | Oil & Gas Operator | Oct 2024 |
| 5 | Meade James C | Oklahoma City, OK 73118-1544 | Gas Operator | Apr 2015 |
| 6 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2024 |
| 7 | Merrick Ward S Inc | Ardmore, OK 73402 | Oil & Gas Operator | Feb 2001 |
| 8 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 9 | Midwest Energy Corporation | Tulsa, OK 74105-6083 | Oil & Gas Operator | Aug 2016 |
| 10 | Mikco Inc | Tulsa, OK 74133 | Oil & Gas Operator | May 2001 |
| 11 | MJM Resources Inc | Norman, OK 73072 | Oil & Gas Operator | Sep 2024 |
| 12 | Montgomery Exploration Co LTD | Dallas, TX 75204-2634 | Oil & Gas Operator | Oct 2024 |
| 13 | Morris Dennis J | Cameron, OK 74932-2186 | Gas Operator | Sep 2024 |
| 14 | Mountain Front Pipeline Co Inc | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2015 |
| 15 | Mueller Thomas C | Fort Smith, AR 72913 | Gas Operator | Aug 2008 |
| 16 | Mueller Thomas C LTD | Oklahoma City, OK 73102-5683 | Gas Operator | Aug 2008 |
| 17 | Muirfield Resources Company | Tulsa, OK 74101-3166 | Oil & Gas Operator | Jun 2024 |
| 18 | Mullen William Company | Edmond, OK 73083-1372 | Oil & Gas Operator | May 1999 |
| 19 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Oct 2024 |