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 1176–1200 of 2,990
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Hansen Lake Dam Roosevelt County | 12 | 1946 | Low | Not Rated |
| Hanson Valley County | 19 | 1965 | Low | Not Rated |
| Hanson #1 Custer County | 16 | 1949 | Low | Not Rated |
| Hanson CO #11 Rosebud County | 15 | 1962 | Low | Not Rated |
| Hanson CO #12 Rosebud County | 15 | 1954 | Low | Not Rated |
| Hanson CO #5 Rosebud County | 18 | 1949 | Low | Not Rated |
| Hanson Coulee Hill County | 12 | 1930 | Low | Not Rated |
| Hanson Creek Dam Fergus County | 72 | 1974 | High | Satisfactory |
| Hanson (Phillips) Phillips County | 20 | 1954 | Low | Not Rated |
| Hanson Reservoir Dam Meagher County | 13 | 1932 | Significant | Not Rated |
| Happy Jack #1 Garfield County | 15 | 1950 | Low | Not Rated |
| Harbaugh #3 Garfield County | 20 | 1952 | Low | Not Rated |
| Harbaugh,C. Garfield County | 15 | 1939 | Low | Not Rated |
| Harbaugh, D. Garfield County | 26 | 1947 | Low | Not Rated |
| Harding 1 Custer County | 26 | 1960 | Low | Not Available |
| Hardin Sewage Lagoon Big Horn County | 9 | 1962 | Low | Not Rated |
| Hard Pan Detention Dam Valley County | 24 | 1954 | Low | Unsatisfactory |
| Hard Rock Detention Dam Valley County | 24 | 1965 | Low | Poor |
| Harfo Richland County | 25 | 1972 | Low | Not Rated |
| Harkin Carter County | 15 | 1979 | Low | Not Rated |
| Harlem Water Supply Blaine County | 8 | 1960 | Low | Not Rated |
| Harlowton Sewage Lagoon Wheatland County | 10 | 1958 | Low | Not Rated |
| Harmes Dam Prairie County | 20 | — | Low | Not Rated |
| Harmon Reservoir Roosevelt County | 15 | 1925 | Low | Not Rated |
| Harmony Garfield County | 18 | 1976 | Low | Not Rated |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.