Holter
Hydro power plant in Cascade County, Montana. 45 MW of nameplate capacity across 3 generators, operated by NorthWestern Energy (MT Hydro).
Also known as Holter Dam Power Plant · EIA plant 2186
Analyst: free account, 1 question a day.
Key facts
- Capacity
- 45 MWNameplate
- Generators
- 3 operatingEIA-860M, August 2026
- Operating since
- July 1918First generator online
- Operator
- NorthWestern Energy (MT Hydro)EIA operator ID 13902
- Grid
- NWMTBalancing authority NWMT
- Price nodes
- None linkedNo verified ISO node
- Location
- Cascade County, MT46.9915, −112.0047
- EIA plant ID
- 2186EIA plant page
Data as of EIA-860M August 2026 (published 2026-09-24). Capacity is nameplate, not live output.
How much power Holter produces
Free · EIA-923Net generation, 2025
248 GWh
247,542 MWh, final
Capacity factor, 2025
51.8%
2024: Not reported
January to July 2026
Not reported
Provisional. 0 of 7 months reported
Range, 2015 to 2025
200.7–344.9
GWh a year. Low 2021, high 2019
| Year | Net generation, MWh | Capacity factor | Months reported |
|---|---|---|---|
| 2000 | Not reported | Not reported | 0 of 12 |
| 2001 | 201,580 | Not reported | 12 of 12 |
| 2002 | 199,901 | Not reported | 12 of 12 |
| 2003 | 250,752 | Not reported | 12 of 12 |
| 2004 | 207,124 | Not reported | 12 of 12 |
| 2005 | 251,413 | Not reported | 12 of 12 |
| 2006 | 279,655 | Not reported | 12 of 12 |
| 2007 | 223,234 | Not reported | 12 of 12 |
| 2008 | 267,506 | Not reported | 12 of 12 |
| 2009 | 319,805 | Not reported | 12 of 12 |
| 2010 | 303,864 | 90.3% | 12 of 12 |
| 2011 | 348,297 | 103.5% | 12 of 12 |
| 2012 | 283,213 | 84.0% | 12 of 12 |
| 2013 | 226,345 | 67.3% | 12 of 12 |
| 2014 | 249,642 | 74.2% | 12 of 12 |
| 2015 | 258,627 | 76.9% | 12 of 12 |
| 2016 | 254,064 | 75.3% | 12 of 12 |
| 2017 | 299,866 | 89.1% | 12 of 12 |
| 2018 | 341,811 | 101.6% | 12 of 12 |
| 2019 | 344,893 | 102.5% | 12 of 12 |
| 2020 | 298,185 | 88.4% | 12 of 12 |
| 2021 | 200,665 | 59.7% | 12 of 12 |
| 2022 | 225,770 | Not reported | 12 of 12 |
| 2023 | 281,585 | Not reported | 12 of 12 |
| 2024 | 265,780 | Not reported | 12 of 12 |
| 2025 | 247,542 | 51.8% | 12 of 12 |
| 2026 (provisional, partial year) | Not reported | Not reported | 0 of 7 |
* 2026 covers January to July and is provisional. Capacity factor is net generation divided by nameplate capacity times the hours of each reported month.
Power prices and basis
Free accountNo verified ISO price node is linked to this plant, or its price history could not load.
Emissions
Free · EPA CAMPDNo EPA emissions units are linked to this plant.
Water use
Free · EIA-923 cooling, USGSNo EIA cooling-water record for this plant in 2024. Plants without steam cooling, such as wind, solar and batteries, do not report cooling water.
Generators
Free · EIA-860M| Generator | Technology | Nameplate MW | Online since |
|---|---|---|---|
| HOL1 | Conventional Hydroelectric | 15.0 | July 1918 |
| HOL2 | Conventional Hydroelectric | 15.0 | July 1918 |
| HOL3 | Conventional Hydroelectric | 15.0 | July 1918 |
Ownership and offtake
ProOwnership and offtake are part of Pro
Owners and their shares, parent companies, and power purchase agreements with their buyers. EIA-860M lists NorthWestern Energy (MT Hydro) as the operator, which is not always the owner.
Modeled data
ProPro adds modeled values for this plant. Everything above stays free.
300 analyst questions a month, plus MCP
Query Holter and 14,224 other projects from Claude or your own tools. Free accounts get 1 question a day.
Power plants near Holter
More plants operated by NorthWestern Energy (MT Hydro)
Questions about Holter
How much power does Holter produce?
Holter reported 247,542 MWh (248 GWh) of net generation in 2025, a 51.8% capacity factor on 45 MW of nameplate capacity.
Where is Holter?
Holter is in Cascade County, Montana, at 46.9915, −112.0047. It is in the NorthWestern Energy (NWMT) balancing area (NWMT).
Who operates Holter?
EIA-860M for August 2026 lists NorthWestern Energy (MT Hydro) as the operator (EIA operator ID 13902). The operator is not always the owner.
When did Holter start operating?
Its first generator began operating in July 1918, according to EIA-860M.
Sources
- EIA-860 2025 (final) and EIA-860M August 2026: plant, generators, capacity, operator and location
- EIA-923 monthly net generation, 2000 to July 2026 (2026 provisional)
- Plant names from OpenStreetMap, © OpenStreetMap contributors (ODbL)
Page updated 2026-10-04 from the InfraMap data build. Methodology · Data sources · EIA plant page