East Fork Dam
Key Takeaway
East Fork Dam is classified as high hazard in Montana. It was completed in 1974 and is 52 years old. Its primary use is recreation. 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 | 62 ft (taller than 97.9% in MT) |
| Dam Length | 2,179 ft |
| Dam Type | Earth |
| Max Storage | 7.2K acre-ft |
| Normal Storage | 1.7K acre-ft |
| Surface Area | 201 acres |
| Drainage Area | 61 sq mi |
| Max Discharge | 28,500 cfs |
| Year Completed | 1974 (52 years old) |
| Year Modified | 1976 |
| NID ID | MT01567 |
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
CITY OF LEWISTOWN
Local Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of East Fork Dam?
East Fork Dam 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 East Fork Dam?
East Fork Dam is owned by CITY OF LEWISTOWN (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was East Fork Dam built?
East Fork Dam was completed in 1974, making it 52 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 East Fork Dam?
East Fork Dam serves the following purposes: Recreation, Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is East Fork Dam?
East Fork Dam has a dam height of 62 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 East Fork Dam last inspected?
East Fork Dam was last inspected on June 15, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.