Stansbury Island is the second largest island within the Great Salt Lake in Utah, USA. Located in Tooele County, it is considered an island even though a dirt causeway connects it to the mainland. Stansbury Island was named after Howard Stansbury, the leader of a government expedition that surveyed the lake in 1851. A biking trail is located on the island. Petroglyphs and two caves large enough to explore are also located on the island. Its peak is Castle Rock, at 6647 feet above sea level. Camping is permitted in most areas.