Lee Mankin is a privately owned earth dam located in Wyoming, specifically in Campbell County near the city of Arvada. Built in 1956, this dam serves multiple purposes including fire protection, stock, and a small fish pond. With a height of 29 feet and a hydraulic height of 24 feet, Lee Mankin has a storage capacity of 155 acre-feet, with a normal storage level of 93 acre-feet and a surface area of 11 acres.

Despite its low hazard potential, Lee Mankin is currently in poor condition as of the last inspection in June 2018. The dam is uncontrolled with a spillway width of 50 feet and no outlet gates. The surrounding area has a drainage area of 3.7 square miles, with the dam situated on the North Fork of Dead Horse Creek. It is crucial for water resource and climate enthusiasts to monitor and maintain dams like Lee Mankin to ensure their structural integrity and safety for surrounding communities.