Lake Pleasant Regional Park is a large outdoors recreation area straddling the Maricopa and Yavapai county border northwest of Phoenix, Arizona. The park is located within the municipal boundaries of Peoria, Arizona, and serves as a major recreation hub for the northwest Phoenix metropolitan area.
The cornerstone of the park is the 10,000 acre, Lake Pleasant, one of the important artificial reservoirs surrounding the Phoenix metropolitan area. Created by the Waddell (Pleasant) Dam, which was finished in 1927, the lake originally had a surface area of 3,700 acres and served as a private irrigation project. At 76 feet high and 2,160 feet long, the original Waddell Dam was, at its completion, the largest agricultural dam project in the world. The Agua Fria River, capturing a large watershed throughout Yavapai County, filled the lake.