Challis, a private irrigation dam located in Crook, Wyoming, along the Antelope Creek, serves as a crucial water resource for the region. Completed in 1914, this Earth dam stands at a height of 24 feet and has a storage capacity of 267 acre-feet, providing essential water for irrigation purposes. The dam's spillway, with a width of 30 feet, helps regulate water flow during high discharge events.

Despite its age, Challis remains in fair condition with a low hazard potential, as assessed in August 2021. The dam is inspected every five years to ensure its structural integrity and safe operation. The risk assessment for Challis indicates a moderate risk level (3), prompting the need for ongoing risk management measures. With Liz Cheney representing the Congressional District 00 in Wyoming, stakeholders are working to maintain the dam's functionality and address any potential risks to ensure the continued availability of water resources for the community.