Rock Reservoir Report
Nearby: Jenson Mcintosh No.2 Enlargement
Last Updated: December 23, 2025
Rock is a privately owned earth dam located in Fremont, Wyoming, designed by Bradley R.
°F
°F
mph
Wind
%
Humidity
Summary
Mortensen and completed in 1978 for flood risk reduction on the off-channel tributary of Antelope Creek. The dam stands at a structural height of 30 feet and has a hydraulic height of 25 feet, with a length of 550 feet and a storage capacity of 48 acre-feet. Despite its low hazard potential and fair condition assessment, Rock is regulated, permitted, inspected, and enforced by the Wyoming State Engineer's Office to ensure its safety and functionality.
With its uncontrolled spillway and one outlet gate, Rock serves as a crucial flood risk reduction structure in the area, providing protection to the surrounding community along HWY 287/789. The dam's primary purpose is flood risk reduction, and it is state-regulated, with regular inspections conducted every five years to assess its condition. Although the dam has a moderate risk assessment rating of 3, Rock meets regulatory guidelines and is equipped to handle potential emergencies through an emergency action plan.
Located in Congressional District 00 of Wyoming, Rock is a vital part of the state's infrastructure for managing water resources and mitigating flood risks in the region. As climate change continues to impact water availability and extreme weather events, the maintenance and proper functioning of structures like Rock are essential for ensuring the safety and resilience of communities in the face of changing environmental conditions.
Year Completed |
1978 |
Dam Length |
550 |
Dam Height |
30 |
River Or Stream |
OFF CHANNEL TRIB ANTELOPE CR |
Primary Dam Type |
Earth |
Surface Area |
4 |
Hydraulic Height |
25 |
Nid Storage |
48 |
Structural Height |
30 |
Outlet Gates |
Uncontrolled - 1 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
30 |
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.
Rock