Montana Dams
2,990 dams tracked by the National Inventory of Dams
Total Dams
2,990
High Hazard
188
6.3%
Poor / Unsatisfactory
132
Average Age
74 yrs
Hazard Classification
High188 (6.3%)
Significant193 (6.5%)
Low2,606 (87.2%)
Condition Assessment
Satisfactory113 (3.8%)
Fair44 (1.5%)
Poor / Unsatisfactory132 (4.4%)
Not Rated2,701 (90.3%)
Federal
278
State
151
Local
84
Private
2,466
Tallest Dams
- Yankee Doodle Tailings Dam570 ft
- Hungry Horse Dam564 ft
- Libby Dam422 ft
- Noxon Rapids260 ft
- Fort Peck Dam256 ft
High Hazard Dams
- Yankee Doodle Tailings DamHigh
- Hungry Horse DamHigh
- Libby DamHigh
- Noxon RapidsHigh
- Fort Peck DamHigh
Poor Condition Dams
All Dams in Montana
Showing 2751–2775 of 2,990
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Big Timber #10 Rosebud County | 26 | 1975 | Low | Not Rated |
| Big Timber #1 Rosebud County | 15 | 1950 | Low | Not Rated |
| Big Sky Lake Dam (Missoula) Missoula County | 7 | — | Significant | Not Rated |
| Big Sky Dam Madison County | 52 | 1973 | High | Satisfactory |
| Big Sky County Wastewater Pond3 Gallatin County | 22 | 1997 | High | Not Rated |
| Big Sky County Wastewater Pond1 Gallatin County | 24 | 1997 | High | Not Rated |
| Big Sage Hen Hill County | 15 | 1973 | Low | Not Rated |
| Big Rock Detention Dam Valley County | 13 | 1961 | Low | Unsatisfactory |
| Big Reservoir Rosebud County | 16 | 1950 | Low | Not Rated |
| Big Railroad Reservoir Garfield County | 15 | 1960 | Low | Not Rated |
| Big Racetrack Lake Dam Granite County | 24 | 1973 | Low | Not Available |
| Big (Phillips) Phillips County | 25 | 1956 | Low | Not Rated |
| Big Mac #1 Garfield County | 35 | 1947 | Low | Not Rated |
| Big Lake (Toole) Toole County | 9 | 1907 | Low | Not Rated |
| Big Lake Missoula County | 30 | 1915 | Significant | Not Rated |
| Big Jugs Hill County | 20 | 1960 | Low | Not Rated |
| Big John M Fergus County | 52 | 1972 | Low | Not Rated |
| Big Gravel Dam 1 Hill County | 20 | 1952 | Low | Not Available |
| Biggerstuf Powder River County | 13 | 1960 | Low | Not Rated |
| Bigfork Diversion Dam Flathead County | 22 | 1910 | High | Poor |
| Big Elk Wheatland County | 21 | 1927 | Significant | Not Rated |
| Big Dumb Bunny Cascade County | 16 | 1972 | Low | Not Rated |
| Big Deal Valley County | 25 | 1952 | Low | Not Rated |
| Big Creek Lake Ravalli County | 12 | 1892 | Significant | Not Rated |
| Big Casino Creek Dam Fergus County | 80 | 1976 | High | Satisfactory |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.