The Trona Pinnacles are an unusual geological feature in the California Desert National Conservation Area. The unusual landscape consists of more than 500 tufa spires (porous rock formed as a deposit when springs interact with other bodies of water), some as high as 140 feet (43 m), rising from the bed of the Searles Lake (dry) basin. The pinnacles vary in size and shape from short and squat to tall and thin, and are composed primarily of calcium carbonate (tufa).