Castle Rock Saddle Dam

Castle Rock Saddle Dam is an earth dam located in Rosebud County, Montana, built in 1976. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Castle Rock Saddle Dam

Castle Rock Saddle Dam is a dam in Rosebud, Montana. The dam is owned by Talen Energy (public utility). It impounds the Tr-east Fork Armells Creek near Forsyth.

The dam stands 20 feet tall and stretches 800 feet across, creates a reservoir covering 140 acres, has a maximum storage capacity of 2,280 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1976, the structure is 50 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 07/15/2014. That was 11 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Montana dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateMontana
CountyRosebud
Nearest CityForsyth
River/StreamTr-east Fork Armells Creek
Coordinates45.88930, -106.63600

Physical Characteristics

Dam TypeEarth
NID Height20 ft
Dam Height20 ft
Dam Length800 ft
Year Completed1976 (50 years old)

Storage & Hydraulics

NID Storage2,280 acre-ft
Max Storage2,280 acre-ft
Normal Storage1,830 acre-ft
Surface Area140 acres
Drainage Area0 sq mi
Max Discharge2,820 cfs

Ownership & Safety

PurposeOther
OwnerTALEN ENERGY
Owner TypePublic Utility
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection07/15/2014
Emergency Action PlanYes

Identifiers

NID IDMT03146
Federal IDMT03146
More InfoState Dam Safety Program

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