Colstrip
Colstrip is a coal plant in Rosebud County, Montana, operated by Talen Montana LLC. No other power plant in Montana has more nameplate capacity; the state has 73 in all. Within the NorthWestern Energy balancing area it is the largest of 52 plants. Its biggest unit, rated at 824 MW, is the largest single generator in Montana. Ownership is shared by six organizations; the largest stake, 25%, is held by Puget Sound Energy Inc.
Nameplate capacity, 2025
1,647 MW
1,480 MW net summer capacity
2 operable units
- Coal steam1,647 MW100%
Unit by unit, 1975 to 2025
operating in 2025retiredbar height follows unit size
Among Montana’s plants
Largest plants in the state by nameplate capacity, with the plants ranked next to this one.
- 1Colstripthis plant
- 2Libby525 MW
- 3Noxon Rapids488 MW
Other rankings
- All US power plants
- 125th of 14,286
- US coal plants
- 40th of 195
- Coal plants in Montana
- 1st of 4
Operable units
| Unit | Technology | Nameplate | Summer | Online | Status |
|---|---|---|---|---|---|
| 3 | Coal steam | 824 MW | 740 MW | 1984 | Operating |
| 4 | Coal steam | 824 MW | 740 MW | 1986 | Operating |
Retired units
Retired capacity here totals 716 MW, mostly coal units.
| Unit | Technology | Nameplate | In service |
|---|---|---|---|
| 1 | Coal steam | 358 MW | 1975–2020 |
| 2 | Coal steam | 358 MW | 1976–2020 |
Who owns it
Shares are weighted by the nameplate capacity of each unit an owner holds.
| Owner | Share of capacity |
|---|---|
| Puget Sound Energy Inc | 25.0% |
| Portland General Electric Co | 20.0% |
| Talen Montana LLC | 15.0% |
| Avista Corp | 15.0% |
| NorthWestern Energy (MT Hydro) | 15.0% |
| PacifiCorp | 10.0% |
Grid and site
- Balancing area
- NorthWestern Energy
- Reliability region
- Western Electricity Coordinating Council
- Highest grid connection voltage
- 500 kV
- Water source
- Yellowstone River
- Nearest town on record
- Colstrip
- Operator type
- Independent producer
- Coordinates
- 45.883°N, 106.614°W
Closest plants
| Plant | Runs on | Capacity | Distance |
|---|---|---|---|
| Colstrip Energy LP | Coal | 46.1 MW | 6.7 mi north |
| Hardin Generator Project | Coal | 116 MW | 48.3 mi west |
| South Mills Solar, LLC | Solar | 3 MW | 50.2 mi west |
| Miles City GT | Natural gas | 23.3 MW | 53.5 mi northeast |
| Clearwater Wind I | Wind | 366 MW | 65.5 mi north |
| Clearwater Wind II | Wind | 103 MW | 67.7 mi north |
| Clearwater Wind III | Wind | 100 MW | 67.7 mi north |
| Clearwater Wind East | Wind | 208 MW | 69.1 mi northeast |