Sibley dam
Sibley
Sibley is a captivating water resource nestled in the heart of Wyoming, specifically in Sheridan County. Managed by the Forest Service, this federal-owned dam on Prune Creek serves primarily for recreational purposes, including fish and wildlife pond activities. Built-in 1938, the Earth-type dam stands at 30 feet tall and stretches 420 feet in length, holding a storage capacity of 635 acre-feet and covering a surface area of 34 acres. With a high hazard potential and a moderate risk assessment rating, Sibley plays a crucial role in maintaining the ecological balance and water supply for the region.
Despite its age, Sibley remains under the vigilant oversight of the Forest Service, with regular inspections and state-regulated maintenance in place. The dam boasts a maximum discharge capacity of 1360 cubic feet per second and an uncontrolled spillway width of 22 feet. While its condition assessment is labeled as "Not Rated," the dam's structural integrity and operational efficiency are upheld through continuous monitoring and risk management measures. In the event of an emergency, the dam is equipped with emergency action plans, ensuring the safety of downstream communities and enhancing overall disaster preparedness.
Located in the scenic city of Dayton, Sibley stands as a testament to sustainable water resource management and environmental stewardship. With its picturesque surroundings and vital role in supporting local wildlife habitats, the dam serves as a key hub for outdoor recreation and nature appreciation. As climate change continues to impact water resources, Sibley remains a resilient structure, safeguarding against potential hazards and contributing to the ecological resilience of 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 Sibley -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Tongue River Near Dayton | 48 cfs | → |
| West Pass Creek Near Parkman | 10 cfs | → |
| East Pass Creek Near Dayton | 12 cfs | → |
| Shell Creek Above Shell Creek Reservoir | 12 cfs | → |
| Little Bighorn River At State Line Nr Wyola Mt | 327 cfs | → |
| Shell Creek Near Shell | 74 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Sibley.
Campgrounds
- Sibley Lake Campground
- Sibley Lake
- Prune Creek
- Prune Creek Campground
- Pine Island Group Campground
- Arrowhead Lodge
Fishing spots
- Tongue River Fishing Site
- Tongue River Fishing East
- Tongue River Fishing West
- Sheridan Fairgrounds Pond
- Upper Paintrock Fishing Site
- Lake Desmet
Paddle runs
- Sf Tongue- Johnson Creek To Confluence With Nf Tongue
- Nf Tongue From Burgess Picnic Ground To Pole Creek
- Bridge At Tongue River Canyon To Burgess Picnic Grounds
- Dry Fork River From Its Confluence With Lake Creek To Confluence With Little Big Horn
- Fools Gold Crossing (Fdr 480) To Wagon Box Creek
- White Creek
More reservoirs
Track Sibley 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 Sibley
Where does the data for Sibley 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 Sibley.