Coon Reservoir Report
Nearby: Sportman Dam Jjjj Russ
Last Updated: December 14, 2025
Coon, located in Sidney, Montana, is a privately owned irrigation dam designed by USDA NRCS and completed in 1950.
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Summary
This Earth dam stands at 15 feet high and stretches 900 feet in length, with a storage capacity of 54 acre-feet. Situated on the North Fork Lone Tree Creek, Coon serves the primary purpose of irrigation, benefiting agriculture in the region with a drainage area of 26.45 square miles.
Owned and regulated by the Montana Department of Natural Resources and Conservation (DNRC), Coon is classified as having low hazard potential and is not currently rated for condition assessment. The dam features a spillway width of 40 feet and is under state jurisdiction for permitting, inspection, and enforcement. With a maximum storage capacity of 54 acre-feet and a normal storage level of 28 acre-feet, Coon plays a vital role in water resource management in Richland County, Montana.
Coon's location in Congressional District 00, Montana, under the oversight of Congressman Greg Gianforte (R), underscores its significance in the local water infrastructure. While the dam has not been modified in recent years and lacks certain safety assessments such as an Emergency Action Plan (EAP), it remains a key asset for irrigation in the area. Water resource and climate enthusiasts will find Coon's design, purpose, and regulatory framework to be of interest in understanding the intersection of water management and agricultural sustainability in Montana.
Year Completed |
1950 |
Dam Length |
900 |
Dam Height |
15 |
River Or Stream |
NORTH FORK LONE TREE CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
15 |
Drainage Area |
26.45 |
Nid Storage |
54 |
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.
Coon