Castle Rock Saddle Dam Reservoir Report
Last Updated: December 5, 2025
Castle Rock Saddle Dam, located in Forsyth, Montana, is a crucial earth dam completed in 1976 with a height of 20 feet and a hydraulic height of 19 feet.
°F
°F
mph
Wind
%
Humidity
Summary
This dam serves multiple purposes, with a primary focus on water resource management. With a storage capacity of 2280 acre-feet and a normal storage level of 1830 acre-feet, the dam plays a significant role in regulating the flow of the TR-East Fork Armells Creek, covering a drainage area of 0.89 square miles.
Managed by a public utility, Castle Rock Saddle Dam stands out for its high hazard potential, prompting regular inspections to ensure its structural integrity. Despite the classification, the dam's condition assessment in 2015 reported it as satisfactory, indicating its reliability in safeguarding the surrounding areas from potential risks. Additionally, the dam's location in Rosebud County, Montana, adds to its importance as a vital infrastructure for water supply and climate resilience in the region.
With a surface area of 140 acres and a maximum discharge capacity of 2820 cubic feet per second, Castle Rock Saddle Dam not only provides essential water storage but also contributes to flood control measures. Its strategic position and operational efficiency make it a key asset in water resource management, highlighting the crucial role of infrastructure like dams in addressing climate challenges and ensuring sustainable water supply for communities in Montana.
Year Completed |
1976 |
Dam Length |
800 |
Dam Height |
20 |
River Or Stream |
TR-EAST FORK ARMELLS CREEK |
Primary Dam Type |
Earth |
Surface Area |
140 |
Hydraulic Height |
19 |
Drainage Area |
0.89 |
Nid Storage |
2280 |
Hazard Potential |
High |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Castle Rock Saddle Dam