Challis is an earth dam located in Crook County, Wyoming, built in 1914. It carries a Low hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 24 ft24 ft tall and 580 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Challis
The primary purpose of Challis is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Crago Land & Livestock, LLP (private). It impounds the Antelope Creek near County Road.
The dam stands 24 feet tall and stretches 580 feet across, creates a reservoir covering 19 acres, and has a maximum storage capacity of 267 acre-feet. Completed in 1914, the structure is over a century old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 08/16/2021.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Wyoming |
| County | Crook |
| Nearest City | County Road |
| River/Stream | Antelope Creek |
| Coordinates | 44.95940, -104.18970 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 24 ft |
| Dam Height | 24 ft |
| Dam Length | 580 ft |
| Year Completed | 1914 (112 years old) |
Storage & Hydraulics
| NID Storage | 267 acre-ft |
| Max Storage | 267 acre-ft |
| Normal Storage | 172 acre-ft |
| Surface Area | 19 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Crago Land & Livestock, LLP |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 08/16/2021 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | WY01590 |
| Federal ID | WY01590 |
| More Info | State Dam Safety Program |