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 1801–1825 of 2,606
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Oster Blaine County | 15 | 1950 | Low | Not Rated |
| Osterized Chouteau County | 11 | 1908 | Low | Not Rated |
| Ostle Teton County | 12 | 1910 | Low | Not Rated |
| Ostleer Dam Petroleum County | 12 | — | Low | Not Rated |
| Ostrich Egg Hill County | 20 | 1950 | Low | Not Rated |
| Otilalda Pondera County | 15 | 1960 | Low | Not Rated |
| Otto Silvan Chouteau County | 9 | 1964 | Low | Not Rated |
| Ottun #3 Big Horn County | 18 | 1950 | Low | Not Rated |
| Ottun #5 Big Horn County | 15 | 1963 | Low | Not Rated |
| Ottun #6 Big Horn County | 16 | 1965 | Low | Not Rated |
| Ottun #8 Big Horn County | 12 | 1965 | Low | Not Rated |
| Ottun #9 Big Horn County | 15 | 1950 | Low | Not Rated |
| Overnight Reservoir Beaverhead County | 17 | 1920 | Low | Not Rated |
| Over The Hill Reservoir Blaine County | 20 | 1962 | Low | Not Rated |
| Ozone Layer Wheatland County | 25 | 1960 | Low | Not Rated |
| Pacabo Gallatin County | 8 | 1956 | Low | Not Rated |
| Padden #2 Carter County | 16 | 1971 | Low | Not Rated |
| Paddle Board Chouteau County | 19 | 1972 | Low | Not Rated |
| Paine McCone County | 26 | 1976 | Low | Not Rated |
| Paint Rock #1 Golden Valley County | 20 | 1972 | Low | Not Rated |
| Palm Ranch #2 Fallon County | 10 | 1961 | Low | Not Rated |
| Pants Beaverhead County | 10 | 1952 | Low | Not Rated |
| Paradise Diversion Dam Blaine County | 21 | 1905 | Low | Not Available |
| Parker Reservoir Powell County | 30 | 1961 | Low | Not Rated |
| Parkers Pond Dam Big Horn County | 18 | 1960 | Low | Not Available |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.