Rainbow

Cascade County, Montana (near Fort Benton)

River/Stream: Missouri River

High Hazard

Failure would likely cause loss of life

Key Facts

Dam Type
Other
Height
44 ft
Dam Length
1,405 ft
Reservoir Storage
1,237 acre-ft
Year Completed
1910
Primary Purpose
Hydroelectric
Owner Type
Private
Max Discharge
125,000 cfs

Condition Assessment

SatisfactoryLast inspected: 2022-08-10

Hazard Classification: High — This describes the potential consequences of dam failure, not the likelihood of failure.

Condition Assessment: Satisfactory — This describes the current physical condition of the dam based on the most recent inspection.

Location

Loading map...

Quick Stats

NID ID
MT00557
State
Montana (MT)
Coordinates
47.53430, -111.20520
Age
116 years

Nearby Dams

External Resources

Data sourced from the National Inventory of Dams (NID). Information may not reflect the most current status of this dam. Hazard classification reflects potential consequences of failure, not the likelihood of failure or the current condition.