Horsethief Lake dam
Horsethief Lake
Horsethief Lake, located in Keystone, South Dakota, is a stunning water resource managed by the USDA Forest Service. Originally completed in 1940, this Earth dam stands at a height of 62 feet, with a hydraulic height of 49 feet, and a structural height of 65 feet. The reservoir has a normal storage capacity of 464 acre-feet and serves primarily for recreational purposes, including fishing and wildlife viewing.
With a drainage area of 4 square miles and a maximum discharge of 990 cubic feet per second, Horsethief Lake offers a serene setting for outdoor enthusiasts to enjoy the beauty of nature. Despite its high hazard potential, the dam's condition assessment is currently not rated, and it last underwent inspection in September 2019. The reservoir's spillway is uncontrolled, and it has a mechanical modification dating back to 2005.
For those interested in exploring water resources and climate in South Dakota, Horsethief Lake is a captivating destination that offers both recreational opportunities and a glimpse into dam engineering and management. In the heart of Pennington County, this reservoir on Pine Creek provides a tranquil escape surrounded by lush landscapes. As stewarded by the Forest Service, this Earth dam stands as a testament to the harmonious coexistence of human activity and natural beauty in the region.
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.
- 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.
- 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.
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, environmental 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.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Horsethief Lake -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Battle Cr Near Keystone Sd | 1 cfs | → |
| Spring Cr Near Keystone Sd | 1 cfs | → |
| Grace Coolidge Cr Nr Game Lodge Nr Custer Sd | 0 cfs | → |
| Rapid Cr Below Pactola Dam Sd | 71 cfs | → |
| French Cr Above Fairburn Sd | 2 cfs | → |
| Rapid Cr Above Canyon Lake Near Rapid City Sd | 51 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Horsethief Lake.
Boat launches
- Calvert Road Pennington County
- Sheridan Lake Road 16451, Rapid City
- Bismark Lake Road Custer County
- Pennington County
- Fsr 450 Pennington County
- Jenney Gulch Picnic Area Fishing Access
Campgrounds
- Horsethief Lake
- Horsethief Lake Campground
- Horse Thief Lake Campground
- Wrinkled Rock
- Grizzly Creek Primitive
- Grizzly Creek - Usfs
Fishing spots
- Horsethief Lake Day Use Site
- Lakota Lake
- Sheridan Lake Complex
- Bismark Lake
- Rapid Creek Trailhead & Fishing Access
- Veterans Point Fishing Pier
More reservoirs
Track Horsethief Lake in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Horsethief Lake
Where does the data for Horsethief Lake come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Horsethief Lake.