New Melones Lake is an artificial lake in the central Sierra Nevada foothills of Calaveras- and Tuolumne County, California, United States near Jamestown. This reservoir created by the construction of the New Melones Dam across the Stanislaus River has a 2,400,000 acre·ft (3,000,000 dam³) capacity with a surface area of 12,500 acres (5,100 ha).