The Bonneville Salt Flats are a 30,000 acre expanse of hard, white salt crust on the western edge of the Great Salt Lake basin in Utah. The salt flats are about 12 miles long and 5 miles wide with total area coverage of just over 46 square miles. Motor vehicle use is limited by seasonal closure during the spring when the salt is moist or has standing water on the surface. Closure dates may vary and will be posted by sign. For more information contact the Salt Lake Field Office.