Neptune Reservoir Report
Nearby: Robbie (Teton) Cloudy Day
Last Updated: December 5, 2025
Neptune, located in Vaughn, Montana, is a privately owned earth dam built in 1920 for fire protection, stock, and small fish pond purposes.
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Summary
Situated on TR-Muddy Creek, this dam has a height of 16 feet and a storage capacity of 67 acre-feet. With a low hazard potential and a condition assessment that is currently not rated, Neptune serves as a critical infrastructure for the local community.
Managed by the Montana Department of Natural Resources and Conservation (DNRC), Neptune is regulated and inspected by the state, ensuring its safety and functionality. While the dam has not been modified in recent years and lacks detailed risk assessment information, it remains an essential resource for water storage and management in Teton County. With its strategic location and primary purpose, Neptune plays a vital role in supporting fire protection efforts and maintaining water supply for livestock and recreational purposes.
Although Neptune's emergency action plan (EAP) status and risk management measures are currently unknown, its operational status and state jurisdiction highlight its importance in the region. With a historic background dating back to the early 20th century, this earth dam continues to provide valuable water resources for the local community while being subject to state regulations and inspections. As water resource and climate enthusiasts, understanding and monitoring the condition of dams like Neptune is crucial for ensuring water security and environmental sustainability in the face of changing climate conditions.
Year Completed |
1920 |
Dam Length |
600 |
Dam Height |
16 |
River Or Stream |
TR-MUDDY CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
16 |
Nid Storage |
67 |
Hazard Potential |
Low |
Nid Height |
16 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Muddy Creek At Vaughn Mt
|
86cfs |
Lake Creek Near Power Mt
|
30cfs |
Sun River Near Vaughn Mt
|
2680cfs |
Teton River Near Dutton Mt
|
83cfs |
Sun River At Simms Mt
|
1620cfs |
Missouri River Near Ulm Mt
|
3150cfs |
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.
Neptune