Lion Lake Dam Reservoir Report

Last Updated: December 5, 2025

Lion Lake Dam, located in Flathead, Montana, was completed in 1948 by the USDA Forest Service and serves primarily for recreational purposes.


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Summary

With a height of 22 feet and a hydraulic height of 14 feet, this earth dam on Whelp Creek has a storage capacity of 1,621 acre-feet, with a normal storage level of 588 acre-feet and a surface area of 43 acres. The dam has a high hazard potential and a moderate risk assessment rating.

Despite its relatively small size, Lion Lake Dam plays a crucial role in the local ecosystem by providing fish and wildlife habitats and recreational opportunities for visitors. The dam is managed and regulated by the Forest Service, ensuring its safe operation and maintenance. With its uncontrolled spillway and outlet gates, Lion Lake Dam serves as an important water resource for the surrounding area, supporting the diverse flora and fauna in the region.

As water resource and climate enthusiasts, the unique design and purpose of Lion Lake Dam make it an intriguing structure to study and appreciate. Its location within the scenic Hungry Horse city, combined with its role in supporting the local environment, makes Lion Lake Dam a valuable asset for both recreational and conservation purposes. The dam's history, construction, and management by the Forest Service add to its significance in ensuring water security and environmental sustainability in the region.

Year Completed

1948

Dam Length

200

Dam Height

22

River Or Stream

WHELP CREEK

Primary Dam Type

Earth

Surface Area

43

Hydraulic Height

14

Drainage Area

200

Nid Storage

1621

Structural Height

22

Outlet Gates

Uncontrolled

Hazard Potential

High

Foundations

Rock, Soil

Nid Height

22
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.