| 1 | Mac Mar Inc | Blairsville, PA 15717-7646 | Oil & Gas Operator | Dec 2025 |
| 2 | Madtick Dev Corp | Punxsutawney, PA 15767-0140 | Oil & Gas Operator | Dec 2024 |
| 3 | Marco Drilling Inc | Monroeville, PA 15146-0278 | Oil & Gas Operator | Dec 2024 |
| 4 | MC123 LLC | Indiana, PA 15701-8718 | Gas Operator | Dec 2025 |
| 5 | MDS Energy Dev LLC | Kittanning, PA 16201-4403 | Oil & Gas Operator | Dec 2025 |
| 6 | MDS Energy LTD | Kittanning, PA 16201-4403 | Gas Operator | Feb 2015 |
| 7 | Meridian Oil & Gas Enterprises Inc | Blairsville, PA 15717-0337 | Oil & Gas Operator | Dec 2003 |
| 8 | Mid East Oil Co | Indiana, PA 15701-5378 | Gas Operator | Dec 2006 |
| 9 | Minter Lee M | Bradford, PA 16701-3763 | Gas Operator | Dec 1991 |
| 10 | Mount Chestnut Dev LLC | Butler, PA 16002-3940 | Gas Operator | Dec 2017 |
| 11 | MTN V Oil & Gas Inc | Indiana, PA 15701-8914 | Oil & Gas Operator | Dec 2025 |