Happy Jack #1 Reservoir Report
Nearby: Sand Cow Southerland Lacosta
Last Updated: December 6, 2025
Happy Jack #1 is a privately owned dam located in Garfield County, Montana, along the TR-SAND CREEK.
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Summary
Completed in 1950, this earth dam stands at a height of 15 feet and has a storage capacity of 76 acre-feet, primarily used for fire protection, stock, and small fish pond purposes. Despite being classified as low hazard potential, the dam is regulated by the Montana Department of Natural Resources and Conservation, with state jurisdiction over its inspection, enforcement, and permitting.
Owned and operated by a private entity, Happy Jack #1 serves as an essential water resource in the region, ensuring water availability for various purposes. With a normal storage capacity of 34 acre-feet and a structural height of 15 feet, the dam plays a vital role in maintaining water levels and providing protection against potential hazards. Although the dam's condition assessment is currently not rated, it undergoes state inspections and enforcement to ensure its integrity and safety.
Situated in a picturesque location within the congressional district of Montana, Happy Jack #1 stands as a testament to water resource management and climate resilience in the region. With its historical significance and continued functionality, this earth dam serves as a key infrastructure for water storage and conservation, showcasing the importance of sustainable water management practices in mitigating the impacts of climate change.
Year Completed |
1950 |
Dam Length |
275 |
Dam Height |
15 |
River Or Stream |
TR-SAND CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
15 |
Nid Storage |
76 |
Hazard Potential |
Low |
Nid Height |
15 |
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.
Happy Jack #1