| 1 | Manuel Corporation | Wichita, KS 67206 | Oil & Gas Operator | Jan 2024 |
| 2 | Marden Producing Company | Edmond, OK 73083 | Gas Operator | Dec 2023 |
| 3 | Marexco | | Oil & Gas Operator | Nov 1994 |
| 4 | Marexco, Inc. | Castle Rock, CO 80104 | Oil & Gas Operator | Apr 2024 |
| 5 | McCoy Petroleum | | Oil & Gas Operator | Aug 1996 |
| 6 | McCoy Petroleum Corporation | Wichita, KS 67207 | Oil & Gas Operator | Mar 2024 |
| 7 | McKelvy A D Oil | | Gas Operator | Feb 1995 |
| 8 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 9 | Merit Energy Company, LLC | Dallas, TX 75240 | Oil & Gas Operator | Jan 2024 |
| 10 | Mid Continent Resources, Inc. | Houston, TX 77060 | Oil & Gas Operator | Apr 2024 |
| 11 | Mid-Continent Energy Corp. | Wichita, KS 67208 | Oil & Gas Operator | Dec 2023 |
| 12 | Mid-Continent Energy, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2020 |
| 13 | Mobil Oil Corpor | | Oil & Gas Operator | Dec 1996 |
| 14 | Murfin Drilling Co., Inc. | Wichita, KS 67202 | Oil & Gas Operator | Feb 2024 |
| 15 | Mustang Drilling | | Oil & Gas Operator | Nov 1996 |