Challis Reservoir Report
Nearby: Lone Tree Bull Creek
Last Updated: December 5, 2025
Challis, a private irrigation dam located in Crook, Wyoming, along the Antelope Creek, serves as a crucial water resource for the region.
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Summary
Completed in 1914, this Earth dam stands at a height of 24 feet and has a storage capacity of 267 acre-feet, providing essential water for irrigation purposes. The dam's spillway, with a width of 30 feet, helps regulate water flow during high discharge events.
Despite its age, Challis remains in fair condition with a low hazard potential, as assessed in August 2021. The dam is inspected every five years to ensure its structural integrity and safe operation. The risk assessment for Challis indicates a moderate risk level (3), prompting the need for ongoing risk management measures. With Liz Cheney representing the Congressional District 00 in Wyoming, stakeholders are working to maintain the dam's functionality and address any potential risks to ensure the continued availability of water resources for the community.
Year Completed |
1914 |
Dam Length |
580 |
Dam Height |
24 |
River Or Stream |
ANTELOPE CREEK |
Primary Dam Type |
Earth |
Surface Area |
19 |
Hydraulic Height |
19 |
Nid Storage |
267 |
Structural Height |
24 |
Outlet Gates |
Other Controlled - 1 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
24 |
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.
Challis