Oil & Gas Companies in Richland County, MT
| Company Name | Company Location | Company Type | Most Recent Production |
| 1 | Eagle Operating Inc | Minot, ND 58701 | Oil & Gas Operator | Aug 2025 |
| 2 | Earthstone Energy, Inc. | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2017 |
| 3 | Earthstone Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2025 |
| 4 | El Paso Production Oil & Gas Co. | Houston, TX 77252 | Oil & Gas Operator | Oct 2025 |
| 5 | Empire North Dakota LLC | Tulsa, OK 74114 | Oil & Gas Operator | Aug 2025 |
| 6 | Encore Operating LP | Plano, TX 75024 | Oil & Gas Operator | May 2025 |
| 7 | Endeavor Energy Resources, LP | Midland, TX 79701 | Oil & Gas Operator | Mar 2025 |
| 8 | Energyquest II, LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Jun 2025 |
| 9 | Enerplus Resources USA Corporation | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 10 | EOG Resources, Inc. | Midland, TX 79702 | Oil & Gas Operator | Oct 2025 |
| 11 | Equinor Energy LP | Austin, TX 78730 | Oil & Gas Operator | Oct 2021 |
| 12 | Equitable Resources Energy Co, Western Region | Billings, MT 59102 | Oil & Gas Operator | May 1997 |
Production numbers shown above are only for Richland County, MT and for the production period listed.