Upper Dry Fork Reservoir Report
Nearby: Lower Dry Fork Eggebrecht Dam
Last Updated: January 11, 2026
Upper Dry Fork is a federally owned earth dam located in Sanders, Montana, managed by the Bureau of Indian Affairs.
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Summary
Built in 1940, this dam stands at a structural height of 40 feet and stretches 2000 feet in length. It serves the primary purpose of controlling the Dry Fork river stream, with a storage capacity of 2815 acre-feet.
The dam's spillway type is controlled, and it has a high hazard potential with a very high risk assessment rating. Despite being in operation for many years, the last inspection was conducted in June 2011, indicating a potential need for further assessments and maintenance. The emergency action plan (EAP) was last revised in March 2015, with no available information on whether it meets guidelines or includes updated inundation maps.
For water resource and climate enthusiasts, Upper Dry Fork presents an intriguing case study in dam management and risk assessment. The dam's critical role in controlling the Dry Fork river stream highlights the importance of regular inspections and maintenance to ensure public safety and water resource management. Further research and attention to the dam's condition and emergency preparedness may be necessary to mitigate potential risks and ensure the long-term sustainability of this vital infrastructure.
Year Completed |
1940 |
Dam Length |
2000 |
River Or Stream |
DRY FORK |
Primary Dam Type |
Earth |
Nid Storage |
2815 |
Structural Height |
40 |
Hazard Potential |
High |
Nid Height |
40 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Mill Cr Ab Bassoo Cr Nr Niarada Mt
|
2cfs |
Flathead River Near Polson Mt
|
12200cfs |
Clark Fork Near Plains Mt
|
18200cfs |
Flathead River At Perma Mt
|
12300cfs |
Thompson River Near Thompson Falls Mt
|
394cfs |
Prospect Creek At Thompson Falls Mt
|
296cfs |
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.
Upper Dry Fork