Great Salt Lake Desert is a large dry lake in northern Utah, USA, and a subregion of the larger Great Basin Desert, noted for Lake Bonneville salt deposits including the Bonneville Salt Flats. The salt pans are remnants of the ancient Lake Bonneville and are composed of a mixture of salts, including sodium chloride, potassium chloride, and magnesium sulfate. The region is arid and receives less than ten inches of precipitation per year, making it one of the driest regions in the United States.