Lazy Y No. 1 is a private water resource structure located in Edgemont, Wyoming, specifically on Lazy Y Draw. This Earth dam, completed in 1957, serves multiple purposes, including fire protection, stock, and small fish pond. With a height of 45 feet and a hydraulic height of 35 feet, it provides a storage capacity of 1,251 acre-feet, with a normal storage level of 849 acre-feet over a surface area of 70 acres.

Despite its low hazard potential, Lazy Y No. 1 is in poor condition as of the last inspection in July 2017. The dam features an uncontrolled spillway with a width of 50 feet and a single slide gate outlet. Its risk assessment indicates a moderate level of risk, with a risk factor of 3. The structure is regulated by the State of Wyoming and is subject to regular inspections, enforcement, and permitting. With its historical significance and functional importance for the local community, Lazy Y No. 1 stands as a testament to the intersection of water resource management and climate considerations in the region.