Johnston Atoll is a 2.8 km² atoll in the North Pacific Ocean at , about one-third of the way from Hawai'i to the Marshall Islands. Johnston Island and Sand Island are natural islands, which have been expanded by coral dredging. North Island (Akau) and East Island (Hikina) are artificial islands formed from coral dredging.

Johnston is an unincorporated territory of the United States, administered from Washington, DC by the United States Fish and Wildlife Service of the United States Department of the Interior as part of the National Wildlife Refuge system. The defense of Johnston Atoll is managed by the military of the United States. The islands are not open to the public.

The climate is tropical but generally dry. Consistent northeast trade winds have little seasonal temperature variation. With elevation ranging from sea level to 5 m at Summit Peak, the islands contain some low-growing vegetation on mostly flat terrain and no natural fresh water resources.

The Atoll's guano deposits were worked until depletion at about 1890. Johnston Atoll was shelled by the Japanese in World War II. The area was subsequently a U.S. nuclear weapons test site and later the site of the Johnston Atoll Chemical Agent Disposal System (JACADS).

Between 1958 and 1975 several sounding rockets were launched from Johnston Island. There were also rockets launched for nuclear tests related to a project called Starfish Prime . The launchpad was at .

The atoll has no indigenous inhabitants, although during the latter twentieth century there was an average of 1,100 U.S. military and civilian contractor personnel present at any given time. The central means of transport to the island was the airport which had a paved, military runway. The islands were wired with 13 outgoing and 10 incoming commercial telephone lines, a 60-channel submarine cable, 22 DSN circuits by satellite, an Autodin with standard remote terminal, a digital telephone switch, the Military Affiliated Radio System (MARS station), a UHF/VHF air-ground radio, and a link to the Pacific Consolidated Telecommunications Network (PCTN) satellite.

The atoll's economic activity was limited to providing services to U.S. military personnel and contractors located on the island. All food and manufactured goods were imported. The base had six 25 MW generators supplied by the base's support contractor. The runway facility was also available to commercial airlines for emergency landings (a fairly common event).

By the end of 2003 the U.S. government transfered jurisdiction of the atoll to the United States Fish and Wildlife Service. Most structures and living facilities (along with those used in the Johnston Atoll Chemical Agent Destruction System [JACADS]) were removed and the runway was visually marked as closed.

See also: Guano Islands Act

External links

• http://www.astronautix.com/sites/johsland.htm Former Johston Island resident, S. Hound