Great Salt Lake in northern Utah is the largest saltwater lake in the Western Hemisphere, a shallow terminal lake whose high salinity comes from minerals left behind as inflowing water evaporates. A remnant of prehistoric Lake Bonneville, it changes dramatically with wet and dry cycles and is fed mainly by the Jordan, Weber, and Bear rivers. The lake has shaped settlement near Salt Lake City, influenced regional climate through lake-effect snow, and drawn attention since early exploration and Mormon settlement. It is also a vital ecological habitat, but modern engineering, drought, and water diversion have contributed to major declines that threaten wildlife, salinity, and air quality.