Browse Dams
3,029 dams in the National Inventory of Dams.
National Inventory of Dams
Browse 3,029 dams from the NID database. Each record includes dam name, location, physical dimensions, hazard potential classification, condition assessment, purpose, owner information, and emergency action plan status. Use the filters below to search by state, hazard level, condition, or keyword.
| Name | State | County | Height (ft) | Hazard | Condition | Year | Purpose |
|---|---|---|---|---|---|---|---|
| Ryan | Montana | Cascade | 82 | High | Satisfactory | 1915 | Hydroelectric |
| Helen B | Montana | Carter | 81 | Low | — | 1966 | Irrigation |
| Pike Creek Dam | Montana | Fergus | 81 | High | Satisfactory | 1977 | Recreation |
| Cataract Creek Dam | Montana | Madison | 80 | High | Unsatisfactory | 1959 | Irrigation |
| Box Elder Creek Dam | Montana | Sheridan | 80 | High | Satisfactory | 1963 | Recreation |
| Big Casino Creek Dam | Montana | Fergus | 80 | High | Satisfactory | 1976 | Irrigation |
| East Dam | Montana | Deer Lodge | 80 | Significant | Satisfactory | — | |
| Bullhook Lower Diversion | Montana | Hill | 77 | High | Satisfactory | 1955 | Flood Risk Reduction |
| Como Dam | Montana | Ravalli | 76 | High | Not Available | 1910 | Irrigation |
| Petrolia | Montana | Petroleum | 76 | High | Poor | 1951 | Irrigation |
| East Fork | Montana | Hill | 76 | High | Satisfactory | 2007 | Recreation |
| Black Lake | Montana | Missoula | 75 | High | Unsatisfactory | 1967 | Recreation |
| Browns Dam | Montana | Hill | 73 | High | Not Rated | 2007 | Irrigation |
| Yellowtail Afterbay Dam | Montana | Big Horn | 72 | High | Not Available | 1966 | Hydroelectric |
| Hanson Creek Dam | Montana | Fergus | 72 | High | Satisfactory | 1974 | Recreation |
| Lower Two Medicine | Montana | Glacier | 70 | High | Satisfactory | 1967 | Irrigation |
| Three Mile Reservoir (L.&C.) | Montana | Lewis and Clark | 70 | High | Poor | 1926 | Irrigation |
| Sheffels Reservoir | Montana | Cascade | 68 | Low | — | 1963 | Fire Protection, Stock, Or ... |
| Sullivan Dam | Montana | Toole | 68 | High | Satisfactory | 1967 | Flood Risk Reduction |
| Moulton Creek Dam #1 | Montana | Silver Bow | 67 | High | Satisfactory | 1907 | Water Supply |
| Castle Rock Reservoir Dam | Montana | Rosebud | 67 | High | Satisfactory | 1976 | Other |
| Lars | Montana | Chouteau | 66 | Low | — | 1950 | Irrigation |
| Cowpath Dam | Montana | Toole | 65 | High | Satisfactory | 1967 | Flood Risk Reduction |
| Tiber Dike | Montana | Liberty | 65 | High | Not Available | 1956 | |
| Bearpaw Lake Dam | Montana | Hill | 64 | High | Satisfactory | 1958 | Recreation |
| Frenchman Dam | Montana | Phillips | 63 | Significant | — | 1953 | Irrigation |
| Thompson Falls - Intake Dam A | Montana | Sanders | 62 | Low | Satisfactory | 1915 | Hydroelectric |
| Hey Ray #2 | Montana | Chouteau | 61 | Low | — | 1958 | Fire Protection, Stock, Or ... |
| Douglas Creek Tailings Dam | Montana | Granite | 60 | Significant | — | — | Tailings |
| Tabor South | Montana | Lake | 60 | High | Poor | 1930 | Recreation |
| Bynum Reservoir Dam | Montana | Teton | 60 | High | Satisfactory | 1926 | Irrigation |
| O'Day #2 | Montana | Cascade | 60 | Low | — | 1956 | Fire Protection, Stock, Or ... |
| Delmoe Lake Dam | Montana | Jefferson | 60 | High | Poor | 1914 | Irrigation |
| Deadmans Basin Dam | Montana | Wheatland | 60 | High | Satisfactory | 1941 | Irrigation |
| Pirate Dam | Montana | Chouteau | 60 | Significant | — | 1982 | Other |
| Flower Creek Dam | Montana | Lincoln | 59 | High | Satisfactory | 2016 | Water Supply |
| Lake Frances East Dam | Montana | Pondera | 59 | High | Satisfactory | 1909 | Irrigation |
| Crazy Sombreo | Montana | Meagher | 58 | Significant | — | 1950 | Irrigation |
| Scott Coulee Dam | Montana | Hill | 58 | High | Satisfactory | 1955 | Flood Risk Reduction |
| Chessman Main Dam | Montana | Lewis and Clark | 57 | High | Fair | 1908 | Water Supply |
| Panasuk Dam | Montana | Roosevelt | 57 | Significant | — | — | Flood Risk Reduction |
| Glacier Lake North Dam | Montana | Carbon | 57 | High | Satisfactory | 1937 | Irrigation |
| Lima | Montana | Beaverhead | 56 | High | Satisfactory | 1934 | Irrigation |
| Ackley Lake Dam | Montana | Judith Basin | 55 | High | Satisfactory | 1938 | Irrigation |
| Georgetown Dam | Montana | Deer Lodge | 55 | High | Satisfactory | 1900 | Hydroelectric |
| Thompson Falls - Main Channel Dam | Montana | Sanders | 54 | Low | Satisfactory | 1915 | Hydroelectric |
| Nilan North Dam | Montana | Lewis and Clark | 54 | High | Satisfactory | 1951 | Irrigation |
| Swift Dike (Pondera) | Montana | Pondera | 53 | High | Satisfactory | 1967 | Irrigation |
| No. Decker Flood Control Reservoir No. 2 | Montana | Big Horn | 52 | Significant | Fair | — | Water Supply |
| Big John M | Montana | Fergus | 52 | Low | — | 1972 | Irrigation |
Frequently Asked Questions
Hazard potential is based on the consequences of dam failure, not the condition of the dam. High hazard means loss of human life is probable. Significant means economic and environmental losses are expected but no probable loss of life. Low means minimal losses are expected. The classification considers downstream population, infrastructure, and environmental resources.
Condition ratings reflect the physical state of the dam based on periodic inspections. Satisfactory means no deficiencies found. Fair means minor issues exist but no immediate action needed. Poor means safety deficiencies require remedial action. Unsatisfactory means the dam is unsafe and immediate corrective action is required.
Yes. Use the search field above to find dams by name. You can also combine the search with state, hazard, and condition filters to narrow your results. Each dam record links to a detail page with complete information.