Black Eagle
Key Takeaway
Black Eagle is classified as high hazard in Montana. It was completed in 1891 and is 135 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 | 35 ft (taller than 92.6% in MT) |
| Dam Length | 1,670 ft |
| Dam Type | Gravity |
| Normal Storage | 1.7K acre-ft |
| Surface Area | 402 acres |
| Drainage Area | 22,100 sq mi |
| Max Discharge | 94,000 cfs |
| Year Completed | 1891 (135 years old) |
| NID ID | MT00558 |
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
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Low Hazard 36 ftFrequently Asked Questions
What is the hazard classification of Black Eagle?
Black Eagle 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 Black Eagle?
Black Eagle is owned by NorthWestern Energy (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Black Eagle built?
Black Eagle was completed in 1891, making it 135 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 Black Eagle?
Black Eagle serves the following purposes: Hydroelectric, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Black Eagle?
Black Eagle has a dam height of 35 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 Black Eagle last inspected?
Black Eagle was last inspected on July 19, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.