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 1526–1550 of 2,990
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Jonas #2 Dawson County | 14 | 1943 | Low | Not Rated |
| Jonas #1 Dawson County | 25 | 1959 | Low | Not Rated |
| Johnstone Pasture Dawson County | 18 | 1950 | Low | Not Rated |
| Johnston and Son Ranch #4 Carter County | 20 | 1964 | Low | Not Rated |
| Johnston Dawson County | 30 | 1954 | Low | Not Rated |
| Johnson (Toole) Toole County | 15 | 1953 | Low | Not Rated |
| Johnson Reservoir Dawson County | 21 | 1937 | Low | Not Rated |
| Johnson, Howard (Pondera) Pondera County | 15 | 1939 | Significant | Not Rated |
| Johnson Farms INC #1 Roosevelt County | 8 | 1955 | Low | Not Rated |
| Johnson #1 Rosebud County | 20 | 1955 | Low | Not Rated |
| John Ragsdale Dam Park County | 19 | 1980 | Low | Not Rated |
| John Lane Teton County | 20 | 1952 | Low | Not Rated |
| John Job Wibaux County | 18 | 1964 | Low | Not Rated |
| John Boy #2 Garfield County | 15 | 1960 | Low | Not Rated |
| John Ball Reservoir McCone County | 16 | 1935 | Significant | Not Rated |
| Jocko Missoula County | 51 | 1937 | High | Poor |
| Jo Fergus County | 30 | 1962 | Low | Not Rated |
| J.L. Big Reservoir Glacier County | 24 | — | Low | Not Rated |
| J Larson #2 Garfield County | 14 | 1960 | Low | Not Rated |
| J King #2 Petroleum County | 12 | 1936 | Low | Not Rated |
| J King #1 Petroleum County | 8 | 1945 | Low | Not Rated |
| J-K-Boyd #1 Rosebud County | 17 | 1950 | Low | Not Rated |
| Jjjj Russ Richland County | 16 | 1962 | Low | Not Rated |
| J Janssen #1 Powder River County | 16 | 1940 | Low | Not Rated |
| J Jacobsen #2 Daniels County | 7 | 1969 | Low | Not Rated |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.