Gibson
Key Takeaway
Gibson is classified as high hazard in Montana. It was completed in 1928 and is 98 years old. Its primary use is irrigation. 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 | 199 ft (taller than 99.7% in MT) |
| Dam Length | 960 ft |
| Dam Type | Concrete |
| Max Storage | 122.0K acre-ft |
| Normal Storage | 99.1K acre-ft |
| Surface Area | 1,420 acres |
| Drainage Area | 575 sq mi |
| Max Discharge | 50,000 cfs |
| Year Completed | 1928 (98 years old) |
| NID ID | MT00571 |
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
RECLAMATION
Federal Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Gibson?
Gibson 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 Gibson?
Gibson is owned by RECLAMATION (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Gibson built?
Gibson was completed in 1928, making it 98 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 Gibson?
Gibson serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Gibson?
Gibson has a dam height of 199 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 Gibson last inspected?
Gibson was last inspected on September 9, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.