Shasta Dam, an arch dam across the Sacramento River at the north end of the Sacramento Valley, California, during its construction in June 1942. The dam mainly serves long-term water storage and flood control in its reservoir, Shasta Lake, and also generates hydroelectric power. At 602 ft (183 m) high, it is the ninth-tallest dam in the United States and forms the largest reservoir in California.Photo: Russell Lee, FSA-OWI; Restoration: Chick Bowen