| 1 | M B Oilfield Services | Oklahoma City, OK 73136 | Oil & Gas Operator | Jun 2003 |
| 2 | M E Klein & Associates LLC | Washington, OK 73093-4663 | Oil & Gas Operator | Feb 2025 |
| 3 | M-B Operating Co., Inc. | Rowlett, TX 75030 | Oil & Gas Operator | Apr 2025 |
| 4 | Mac Laskey Kelly Oilfield | El Dorado, KS 67042 | Oil & Gas Operator | Feb 2025 |
| 5 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Feb 2025 |
| 6 | Magaw & Zimmer | Perry, OK 73077-1055 | Oil & Gas Operator | Aug 2013 |
| 7 | Magnum Energy Inc | Norman, OK 73072-2403 | Oil & Gas Operator | Feb 2025 |
| 8 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 9 | Marathon Oil Company | Houston, TX 77024 | Oil & Gas Operator | Feb 2025 |
| 10 | Mark A Meier Dba MSC Oil And Gas Co | Oklahoma City, OK 73105 | Oil & Gas Operator | Feb 2025 |
| 11 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Jan 2025 |
| 12 | Marshall Oil Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Apr 2017 |
| 13 | Mason Robert A Production Co | Edmond, OK 73013-9102 | Oil & Gas Operator | May 2013 |
| 14 | Matador E & P Company Inc | | Oil & Gas Operator | May 2020 |
| 15 | Mathews Exploration Corporation | Oklahoma City, OK 73155-5328 | Oil & Gas Operator | Mar 2015 |
| 16 | Mator LLC | Hennessey, OK 73742-1235 | Oil & Gas Operator | Feb 2025 |
| 17 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 18 | Meadowbrook Oil Corporation Of Ok Inc | Del City, OK 73115-3608 | Oil & Gas Operator | Feb 2025 |
| 19 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 20 | Mercer Pet Management Inc | Edmond, OK 73013-6677 | Oil & Gas Operator | Jan 2011 |
| 21 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2025 |
| 22 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2025 |
| 23 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 24 | Mito Resources LLC | Edmond, OK 73013 | Oil & Gas Operator | Feb 2025 |
| 25 | Monty L Hott Production Corporation | Oklahoma City, OK 73142 | Oil & Gas Operator | Jan 2025 |
| 26 | Moore & Moore Energy Inc | Purcell, OK 73080-0674 | Oil & Gas Operator | Dec 2012 |
| 27 | Moore Clay | Bradenton, FL 34211 | Oil & Gas Operator | Jan 2025 |
| 28 | Moran-K Oil LLC | Seminole, OK 74868 | Oil & Gas Operator | Feb 2025 |
| 29 | Mott Petroleum Corporation | Sugar Land, TX 77487 | Oil & Gas Operator | Aug 2024 |
| 30 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Apr 2025 |
| 31 | Muegge, Clay A. | Lamont, OK 74643 | Oil & Gas Operator | Feb 2025 |
| 32 | Mullins Jimmy R Dba Southcreek Petroleum Co | Dibble, OK 73031 | Oil & Gas Operator | Jan 2021 |
| 33 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |