| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Encana Oil & Gas (USA) Inc. | Denver, CO 80202 | Oil & Gas Operator | Oct 2020 |
| 2 | Enclave Operating, LLC | Shelby, MT 59474 | Oil & Gas Operator | May 2014 |
| 3 | Energy Equity Company | Columbus, MT 59019 | Oil & Gas Operator | Aug 2025 |
| 4 | Enneberg Oil & Gas | Kevin, MT 59454 | Oil Operator | Jul 2025 |
| 5 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 6 | Equitable Resources Energy Co, Western Region | Billings, MT 59102 | Oil & Gas Operator | May 1997 |