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 2001–2025 of 2,606
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Deminish Teton County | 10 | 1952 | Low | Not Rated |
| Delmar Liberty County | 20 | 1914 | Low | Not Rated |
| Delaney #2 Petroleum County | 20 | 1959 | Low | Not Rated |
| Deiphobus Cascade County | 10 | 1953 | Low | Not Rated |
| Deigratia Chouteau County | 20 | 1960 | Low | Not Rated |
| Deianira Chouteau County | 20 | 1960 | Low | Not Rated |
| Dees Brothers Hill County | 16 | 1938 | Low | Not Rated |
| Deer Lodge Sewage Lagoon Powell County | 8 | 1960 | Low | Not Rated |
| Deer Creek Dawson County | 30 | 1936 | Low | Not Rated |
| Deerborn Reservoir Lewis and Clark County | 20 | 1900 | Low | Not Rated |
| Deep Cut Detention Dam Valley County | 22 | 1960 | Low | Fair |
| Deep Coulee Petroleum County | 25 | 1971 | Low | Not Rated |
| Deep Can Teton County | 35 | 1935 | Low | Not Rated |
| Decuman Teton County | 15 | 1965 | Low | Not Rated |
| Decock #3 Treasure County | 15 | 1949 | Low | Not Rated |
| Decarboxylation Teton County | 20 | 1960 | Low | Not Rated |
| Decameter Teton County | 20 | 1960 | Low | Not Rated |
| Dean S #2 Dawson County | 20 | 1946 | Low | Not Rated |
| Dean S #1 McCone County | 20 | 1943 | Low | Not Rated |
| Dealers Choice McCone County | 20 | 1944 | Low | Not Rated |
| Deadmans Basin Water Supply Canal Storage Reservoir #6 Wheatland County | 28 | — | Low | Not Rated |
| Deadmans Basin Water Supply Canal Storage Reservoir #2 Wheatland County | 33 | — | Low | Not Rated |
| Dead Horse Detention Dam Valley County | 16 | 1960 | Low | Satisfactory |
| D Drum Phillips County | 12 | 1960 | Low | Not Rated |
| Dawson Ranch #1 Cascade County | 30 | 1948 | Low | Not Rated |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.