Castor (Choteau) Reservoir Report
Nearby: Squiggles #2 Squiggles #1
Last Updated: December 5, 2025
Castor (Choteau) is a privately owned dam located in Chouteau County, Montana, near the city of Loma.
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Summary
Built in 1960, this earth dam stands at a height of 20 feet and serves multiple purposes including fire protection, stock watering, and small fish pond management. With a storage capacity of 51 acre-feet, it primarily draws water from the TR-SHEEP COULEE river or stream for its operations, making it a vital resource for the local community.
Managed by the Montana Department of Natural Resources and Conservation (DNRC), Castor (Choteau) has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment. Despite not having a designated emergency action plan in place, the dam is regularly inspected, permitted, and regulated to ensure its safety and compliance with state jurisdiction. With its close proximity to the Omaha District of the US Army Corps of Engineers, Castor (Choteau) plays a crucial role in water resource management and climate resilience efforts in the region.
Although the dam has not undergone any significant modifications or risk assessments, its stable condition and low hazard potential make it a reliable asset for fire protection, irrigation, and wildlife habitat enhancement. As water resources continue to be a focal point for environmental sustainability and climate adaptation, Castor (Choteau) stands as a testament to responsible private ownership and state regulation in managing water infrastructure for the benefit of both human and ecological communities in Montana.
Year Completed |
1960 |
Dam Length |
175 |
Dam Height |
20 |
River Or Stream |
TR-SHEEP COULEE |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Nid Storage |
51 |
Hazard Potential |
Low |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Marias River Near Loma Mt
|
335cfs |
Teton River At Loma Mt
|
30cfs |
Marias River Near Chester Mt
|
249cfs |
Missouri River At Fort Benton Mt
|
4720cfs |
Missouri River At Virgelle Mt
|
4290cfs |
Teton River Near Dutton Mt
|
83cfs |
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.
Castor (Choteau)