Cowpath Dam Reservoir Report
Nearby: Sullivan Dam Shelby Sewage Lagoon
Last Updated: December 6, 2025
Cowpath Dam, also known as Lake Shel-Oole, is a key flood risk reduction structure located in Toole County, Montana.
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Summary
Built in 1967 by the USDA NRCS, this earth dam stands at a height of 49 feet and has a hydraulic height of 65 feet, with a storage capacity of 940 acre-feet. The dam's primary purpose is flood risk reduction, serving as a vital protective barrier along the TR-Marias River.
Managed by the local government and regulated by the Montana Department of Natural Resources and Conservation (DNRC), Cowpath Dam has a satisfactory condition assessment and a high hazard potential. Despite its age, the dam has undergone regular inspections, with the last one conducted in June 2021. With a moderate risk level and a spillway width of 70 feet, Cowpath Dam plays a crucial role in safeguarding the surrounding community of Shelby from potential flooding events.
As a significant infrastructure in the region, Cowpath Dam serves as a testament to effective collaboration between federal and state agencies in ensuring the safety and resilience of water resources in Montana. With a solid design by the NRCS and ongoing monitoring and maintenance efforts, the dam continues to fulfill its essential function of flood risk reduction, highlighting the importance of sustainable water management practices in the face of changing climate conditions.
Year Completed |
1967 |
Dam Length |
1425 |
Dam Height |
49 |
River Or Stream |
TR-MARIAS RIVER |
Primary Dam Type |
Earth |
Surface Area |
17.4 |
Hydraulic Height |
49 |
Drainage Area |
520 |
Nid Storage |
940 |
Structural Height |
65 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
High |
Foundations |
Rock, Soil |
Nid Height |
65 |
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.
Cowpath Dam