Ryan

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateMontana
CountyCascade
Nearest CityFort Benton
River/StreamMissouri River
Coordinates47.56880, -111.12510

Physical Characteristics

Dam TypeGravity
NID Height82 ft
Dam Height61 ft
Dam Length1,465 ft
Year Completed1915 (111 years old)

Storage & Hydraulics

NID Storage3,653 acre-ft
Max Storage3,613 acre-ft
Normal Storage3,653 acre-ft
Surface Area168 acres
Drainage Area23,080 sq mi
Max Discharge188,000 cfs
Spillway TypeControlled

Ownership & Safety

PurposeHydroelectric
OwnerNorthWestern Energy
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection07/18/2022
Emergency Action PlanYes

Identifiers

NID IDMT00555
Federal IDMT00555
More InfoState Dam Safety Program

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