Larry's Last Chance Reservoir Report
Nearby: Sore Finger Ikey
Last Updated: December 5, 2025
Larry's Last Chance is a vital earth dam located in Big Horn, Wyoming, with the primary purpose of flood risk reduction.
°F
°F
mph
Wind
%
Humidity
Summary
Built in 1965, this structure stands at 25 feet tall and spans 353 feet in length, providing storage for up to 60 acre-feet of water from Larry's Draw. Despite its low hazard potential, the dam is in poor condition as of its last assessment in June 2017, with a moderate risk rating of 3.
While the dam has not been modified in recent years, it is regularly inspected every 5 years to ensure its integrity and safety. With a drainage area of 0.4 square miles and a maximum discharge capacity of 227 cubic feet per second, Larry's Last Chance serves as a critical component in the local water resource management system. Although the dam currently lacks outlet gates and proper emergency action plans, its location in a low-risk area minimizes the immediate threat to downstream communities.
As water resource and climate enthusiasts continue to monitor and assess the condition of Larry's Last Chance, it remains a key asset in flood risk reduction efforts in the region. With ongoing inspections and maintenance, stakeholders strive to uphold the dam's functionality and safeguard its surrounding environment from potential hazards.
Year Completed |
1965 |
Dam Length |
353 |
Dam Height |
25 |
River Or Stream |
LARRY'S DRAW |
Primary Dam Type |
Earth |
Surface Area |
5 |
Hydraulic Height |
20 |
Drainage Area |
0.4 |
Nid Storage |
60 |
Structural Height |
25 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
25 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Bighorn River At Kane
|
1340cfs |
Shoshone River Near Lovell
|
460cfs |
Bighorn River At Basin
|
996cfs |
Shell Creek Near Shell
|
74cfs |
Shoshone River Below Buffalo Bill Reservoir
|
315cfs |
Greybull River At Meeteetse
|
338cfs |
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.
Larry's Last Chance