American, river, 30 mi (48 km) long, rising in N central Calif. in the Sierra Nevada and flowing SW into the Sacramento River at Sacramento. The discovery of gold at Sutter's Mill (see Sutter, John Augustus) along the river in 1848 led to the California gold rush of 1849. The American is a magnet for rafters. The proposed Auburn Dam, where construction was stopped after a 1975 earthquake, is highly controversial.
