JOHNSTON AND SAND ISLANDS

unincorporated territory of the U.S. in the central Pacific Ocean, 715 miles (1,150 km) southwest of Honolulu. A raised coral atoll formation measuring 3,000 by 600 feet (900 by 180 m), the two islands have a total land area of 320 acres (130 hectares). Johnston, the larger, rises to 44 feet (13 m) at Summit Peak. Both are within a 7.5-mile (12-kilometre) semicircular reef. Rainfall is sparse, and there are no sources of fresh water. Vegetation is limited to bunch grass and herbs. Sand Island is uninhabited. Sighted in 1807 by an English mariner, Captain C.J. Johnston, the islands were uninhabited and remained unclaimed until 1858, when both the United States (under the Guano Act of 1856) and the Kingdom of Hawaii laid claim. The islands' guano deposits were exhausted by 1908. Declared a bird sanctuary in 1926 under the administration of the U.S. Department of Agriculture, the atoll was placed under the U.S. Navy in 1934. By 1941 a naval air station had been built, the landing field taking up almost the full length of the island. Johnston was transferred to U.S. Air Force jurisdiction in 1948 and was associated with U.S. nuclear-weapons tests until 1962. The island has been managed by the Defense Nuclear Agency since 1974. A facility for incinerating U.S. chemical weapons stockpiles went into operation on the island in the early 1990s. Pop. (1980) 327.