Power plant · EIA plant code 67766
Yellowstone County Generating Station
- Operator
- NorthWestern Energy (MT wind/thermal)
- Location
- Yellowstone, MT (county level only)
- Balancing authority
- NorthWestern Energy (NWMT) (NWMT)
- Nameplate capacity
- 207 MW
- Summer capacity
- 165.6 MW
U.S. Energy Information Administration · Annual Electric Generator Report (Form EIA-860) · data for 2025 · as of Sep 10, 2026 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Sep 10, 2027. Last checked for an update: Oct 31, 2026.
Generation in 2025
- Net generation
- 383,412 MWh
- Capacity factor
- 21.1%
Capacity factor is net generation divided by nameplate capacity times the hours each generator was in service that year, counted by month.
U.S. Energy Information Administration · Power Plant Operations Report (Form EIA-923) · data for 2025 · as of Sep 11, 2026 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Sep 11, 2027. Last checked for an update: Oct 31, 2026.
Emissions
This plant is not in eGRID2023 (revision 2).
U.S. Environmental Protection Agency · Emissions & Generation Resource Integrated Database (eGRID) · data for 2023 · as of Jun 16, 2025 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Jan 31, 2026. Last checked for an update: Oct 31, 2026.
Generators
| Generator | Technology | Energy source | Nameplate | Operating since | Status |
|---|---|---|---|---|---|
| YGS01 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS02 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS03 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS04 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS05 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS06 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS07 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS08 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS09 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS10 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS11 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS12 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS13 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS14 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS15 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS16 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS17 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
| YGS18 | Natural Gas Internal Combustion Engine | NG | 11.5 MW | 2024 | Operable · As of September 2026 (EIA-860M): (OP) Operating |
U.S. Energy Information Administration · Monthly Update to the Annual Electric Generator Report (Form EIA-860M) · data for 2026-09 · as of Oct 23, 2026 · retrieved Oct 31, 2026 · CC-BY-4.0 May be out of date. The next release was due by Nov 23, 2026. Last checked for an update: Oct 31, 2026.