| 1 | Makar Production Company | Graham, TX 76450 | Oil & Gas Operator | Oct 2025 |
| 2 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 3 | Marsh Operating Company | Dallas, TX 75221 | Oil & Gas Operator | Jun 2025 |
| 4 | Matador Operating Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2003 |
| 5 | Maxus Exploration Company | Dallas, TX 75201 | Oil & Gas Operator | Jan 1995 |
| 6 | Maxwell Resources Corporation | Oklahoma City, OK 73116-7746 | Oil & Gas Operator | Apr 2009 |
| 7 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | Oct 2025 |
| 8 | McNic Oil & Gas Midcontinent,Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 1999 |
| 9 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 10 | Mer Resources | Edmond, OK 73013 | Oil & Gas Operator | Oct 2025 |
| 11 | Merex Resources, Inc. | Amarillo, TX 79159 | Oil & Gas Operator | Sep 2019 |
| 12 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 13 | Meridian Oil Production Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 2024 |
| 14 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 15 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | Oct 2025 |
| 16 | Mexco Energy Corporation | Midland, TX 79702 | Oil & Gas Operator | Feb 2020 |
| 17 | Midcoast G & P (East Texas) L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 18 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 19 | Midpar L.P. | Midland, TX 79702 | Oil & Gas Operator | Feb 1995 |
| 20 | Midstates Petroleum Company LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 21 | Midwestern Exploration Co. | Edmond, OK 73013 | Oil & Gas Operator | May 2025 |
| 22 | Minco Oil And Gas Co. | Pampa, TX 79066 | Oil & Gas Operator | Aug 2024 |
| 23 | MMGL TXPH, LLC | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 24 | Mobil Oil Corporation | Houston, TX 77210 | Oil & Gas Operator | Jun 2016 |
| 25 | Mobil Producing TX. & N.M. Inc. | Spring, TX 77389 | Oil & Gas Operator | Oct 2025 |
| 26 | Mon Corp. | Pampa, TX 79066 | Oil & Gas Operator | Oct 2025 |
| 27 | Monitor O&G, L.L.C. | Frisco, TX 75034 | Oil & Gas Operator | Jan 2016 |
| 28 | Moody Energy Co. | Canadian, TX 79014 | Oil & Gas Operator | Dec 2004 |
| 29 | Mustang Fuel Corporation | Oklahoma City, OK 73114 | Oil & Gas Operator | Jul 2025 |
| 30 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |