| 1 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | May 2024 |
| 2 | Mac Laskey Kelly Oilfield | El Dorado, KS 67042 | Oil & Gas Operator | Feb 2024 |
| 3 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Feb 2024 |
| 4 | Maguire Oil Company | Dallas, TX 75270 | Oil & Gas Operator | Mar 2015 |
| 5 | Marymac Company | Dallas, TX 75219-2362 | Oil & Gas Operator | Mar 2015 |
| 6 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Feb 2024 |
| 7 | Medders Oil Company | Wichita Falls, TX 76308 | Oil & Gas Operator | May 2024 |
| 8 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 9 | Mendell Petroleum Corporation | Castle Rock, CO 80104-9045 | Oil & Gas Operator | Sep 2004 |
| 10 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | May 2024 |
| 11 | Mermac Operating Company Inc | Norman, OK 73072 | Oil & Gas Operator | Mar 2015 |
| 12 | Michaels, Bobby W | | Oil Operator | Nov 1998 |
| 13 | Mid-Con Central Expl Co | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2014 |
| 14 | Mid-Con Energy Operating, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | May 2020 |
| 15 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2024 |
| 16 | Midstate Oil & Gas Company | Shawnee, OK 74802-1807 | Oil & Gas Operator | Jan 2024 |
| 17 | Moore Richard L | Morris, OK 74445 | Oil Operator | Aug 2013 |
| 18 | Morgan Energy Corporation | Englewood, CO 80110 | Oil & Gas Operator | Mar 2006 |
| 19 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | May 2024 |
| 20 | Mud Operations Inc | Ames, OK 73718-9501 | Oil & Gas Operator | Feb 2024 |
| 21 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Feb 2024 |