| 1 | M & M Exploration, Inc. | Westminster, CO 80031 | Oil & Gas Operator | Mar 2025 |
| 2 | M E Klein & Associates LLC | Washington, OK 73093-4663 | Oil & Gas Operator | Mar 2025 |
| 3 | Mack Energy Co. | Duncan, OK 73534 | Oil & Gas Operator | Mar 2025 |
| 4 | Mackellar Inc | Oklahoma City, OK 73116-7101 | Oil & Gas Operator | Mar 2025 |
| 5 | Maguire James Q Inc | Norman, OK 73070-1748 | Oil & Gas Operator | Jun 2011 |
| 6 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 7 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Mar 2025 |
| 8 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Apr 2025 |
| 9 | Marjo Operating Company Inc | Tulsa, OK 741010729 | Oil & Gas Operator | Feb 2025 |
| 10 | Marjo Operating Mid-Continent LLC | Tulsa, OK 74103 | Oil & Gas Operator | Mar 2025 |
| 11 | Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Feb 2025 |
| 12 | Marshall Oil Corporation | Oklahoma City, OK 73154 | Oil & Gas Operator | Apr 2017 |
| 13 | Matador E & P Company Inc | | Oil & Gas Operator | May 2020 |
| 14 | Mathews & Casselman Oil Inc | Morris, OK 74445 | Oil & Gas Operator | Dec 2021 |
| 15 | Maverick Brothers Resources LLC | Enid, OK 73701 | Oil & Gas Operator | Feb 2025 |
| 16 | May Petroleum, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 17 | McCool John E | Youngsville, PA 16371 | Oil & Gas Operator | Mar 2025 |
| 18 | McNic Oil & Gas Midcontinent | Oklahoma City, OK 73154-0526 | Oil & Gas Operator | May 2024 |
| 19 | McOr Oil & Gas Corp | Houston, TX 77002 | Oil & Gas Operator | Oct 2013 |
| 20 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 21 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 22 | Mep Operating LLC | Houston, TX 77056-2733 | Oil & Gas Operator | Mar 2025 |
| 23 | Mer Resources Inc | Edmond, OK 73013-7662 | Oil & Gas Operator | Mar 2015 |
| 24 | Mesa Operating LP | Irving, TX 75039-3746 | Oil & Gas Operator | Oct 2010 |
| 25 | Metropolitan Resources Corp | Tulsa, OK 74169-1734 | Oil & Gas Operator | Mar 2015 |
| 26 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Jun 2025 |
| 27 | Mid Center Oil Company | | Oil & Gas Operator | Mar 2014 |
| 28 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2025 |
| 29 | Midland TMG Inc. | Midland, TX 79705 | Oil & Gas Operator | Apr 2017 |
| 30 | Midway Operating Company, L.L.C. | Woodward, OK 73802 | Oil & Gas Operator | Jun 2025 |
| 31 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 32 | Miller Oil & Gas Co | Okmulgee, OK 74447 | Oil & Gas Operator | Oct 2017 |
| 33 | MJM Resources Inc | Norman, OK 73072 | Oil & Gas Operator | Mar 2025 |
| 34 | MLC Resources LLC | Kingfisher, OK 73750-0364 | Oil & Gas Operator | Jan 2025 |
| 35 | Monroe Natural Gas Inc | Norman, OK 73071 | Oil & Gas Operator | Feb 2025 |
| 36 | Monterey Production Company LLC | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2025 |
| 37 | Montgomery Exploration Co LTD | Dallas, TX 75204-2634 | Oil & Gas Operator | Mar 2025 |
| 38 | MT Energy LLC | Waskom, TX 75692 | Oil & Gas Operator | Jun 2025 |
| 39 | Mueller Thomas C | Fort Smith, AR 72913 | Gas Operator | Aug 2008 |
| 40 | Mustang Fuel Corp. Of Oklahoma | Oklahoma City, OK 73106 | Oil & Gas Operator | Nov 2016 |
| 41 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2025 |
| 42 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |