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 |
|---|---|---|---|---|
| Two D-4 Ranch Carter County | 20 | 1952 | Low | Not Rated |
| Two Dollar Bill Meagher County | 15 | 1940 | Low | Not Rated |
| Twodot Wheatland County | 31 | 1953 | Low | Not Rated |
| Two Forks Detention Dam Valley County | 24 | 1956 | Low | Poor |
| Two Turtle Dam Toole County | 20 | 1960 | Low | Not Rated |
| Tye Chouteau County | 20 | 1955 | Low | Not Rated |
| Ucaliptus Toole County | 10 | 1950 | Low | Not Rated |
| Ugly Blaine County | 15 | 1943 | Low | Not Rated |
| Ulmer Lake Rosebud County | 20 | 1953 | Low | Not Rated |
| U.L.T. Detention Dam Valley County | 18 | 1966 | Low | Poor |
| Umstead Reservoir Fergus County | 24 | 1948 | Low | Not Rated |
| Underdal #1 Toole County | 19 | 1963 | Low | Not Rated |
| Underdal #2 Toole County | 25 | 1938 | Low | Not Rated |
| U N Reservoir Hill County | 20 | 1940 | Low | Not Rated |
| Upper Baker Dam Fallon County | 32 | 1975 | High | Satisfactory |
| Upper Branham Madison County | 6 | 1980 | Significant | Not Rated |
| Upper Dry Fork East Dike Sanders County | 14 | 1942 | Low | Poor |
| Upper Glasston North Dam Sweet Grass County | 20 | 1912 | High | Poor |
| Upper Glasston West Dam Sweet Grass County | 22 | 1912 | High | Poor |
| Upper Magpie Reservoir Dawson County | 15 | 1960 | Low | Not Rated |
| Upper O'Dell Coulee Reservoir McCone County | 24 | 1952 | Low | Not Rated |
| Upper Prairie Goat Det. Dam Dawson County | 31 | 1962 | Low | Unsatisfactory |
| Upper Twin Lakes Ravalli County | 14 | 1964 | Low | Not Rated |
| Upsilon Glacier County | 20 | 1930 | Low | Not Rated |
| Us#13 Dam Rosebud County | 26 | — | Low | Not Rated |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.