The present 160-mile shoreline of Don Pedro Lake was created in 1971 when the New Don Pedro Dam was completed. Lake Don Pedro has 13,000 surface-acres of water, making it the fifth largest reservoir in California.
Prior to 1971, a concrete dam built in 1923 backed the Tuolumne river some 1.5 miles upstream from the new dam's location, creating a much smaller lake than the present one. The old dam is still in place, but 250 feet below water.
The present earth and rock fill dam was built by the City of San Francisco, the Turlock Irrigation District and the Modesto Irrigation District. It rises some 585 feet above the old streambed of the tuolumne river, creating a maximum lake level/elevation of 830 feet above sea level.
The recreation facilities are maintained and operated by the Don Pedro Recreation Agency, an entity of the reservoir owners and governed by the Don Pedro Board of Control.