Salton Sea, saline lake, in the lower Colorado Desert, southern California, U.S. The area that is now the lake was formerly a salt-covered sink or depression (a remnant of prehistoric Lake Cahuilla) about 280 feet (85 metres) below sea level until 1905–06, when diversion controls on the Colorado River broke a few miles below the California-Mexico border and floodwaters rushed northward, filling the depression. Subsequent deepening of the sink was stopped in 1907, when a...