Morony
Key Takeaway
Morony is classified as high hazard in Montana. It was completed in 1929 and is 97 years old. Its primary use is hydroelectric. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.
Physical Details
| Dam Height | 70 ft (taller than 98.3% in MT) |
| Dam Length | 842 ft |
| Dam Type | Gravity |
| Max Storage | 13.9K acre-ft |
| Normal Storage | 13.6K acre-ft |
| Surface Area | 304 acres |
| Drainage Area | 23,292 sq mi |
| Max Discharge | 153,000 cfs |
| Year Completed | 1929 (97 years old) |
| NID ID | MT00563 |
Safety Information
Loss of human life is likely if the dam fails.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
NorthWestern Energy
Private
Nearby Dams
Ryan
Cascade, MT
High Hazard 61 ftPrairie Nest Ranch 1
Cascade, MT
Low Hazard 30 ftO'Day #2
Cascade, MT
Low Hazard 60 ftPrairie Nest Ranch 4
Cascade, MT
Low Hazard 28 ftPrairie Nest Ranch 3
Cascade, MT
Low Hazard 44 ftPrairie Nest Ranch 2
Cascade, MT
Low Hazard 20 ftCochrane
Cascade, MT
High Hazard 100 ftCharlotts Webb
Cascade, MT
Low Hazard 20 ftFrequently Asked Questions
What is the hazard classification of Morony?
Morony is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Morony?
Morony is owned by NorthWestern Energy (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Morony built?
Morony was completed in 1929, making it 97 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.
What is the primary purpose of Morony?
Morony serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Morony?
Morony has a dam height of 70 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.
When was Morony last inspected?
Morony was last inspected on July 20, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.