SACRAMENTO RIVER, in central California, rises in the northern part of the state, near Mount Shasta, and flows southward about 320 miles (512 km) to join the San Joaquin River flowing from the south. Their waters empty into Suisun Bay, an arm of San Francisco Bay. The Sacramento and San Joaquin are the principal rivers of California, draining the great Central Valley between the Sierra Nevada and the Coast Ranges. This valley is one of the foremost agricultural regions of the United States. Among the important tributaries of the Sacramento are the Pit and the Feather rivers.
The Sacramento is a key factor in the Central Valley Project, which was begun in the 1930’s to provide flood control, store water for irrigation of farmlands and to supply California’s cities, and to furnish hydroelectric power. Shasta Dam, on the Sacramento below the mouth of the Pit, and Keswick Dam, farther downstream, are major units in this development.