16 43 N, 169 31 W  Located 1,328 km southwest from Honolulu, Hawaii, about one-third of the way from Hawaii to the Marshall Islands. Americans mined the guano deposits until the late 1880s. Johnston and Sand Islands were designated wildlife refuges in 1926.

Mavis Reconnancence Mission
H6K Mavis flying boat flew reconnancence on the atoll when Ensign Tomaro flew a successful observed the atoll prior to the battle of Midway in June 1942.

Military Usage
The US Navy took over the atoll in 1934, and subsequently the US Air Force assumed control in 1948. The site was used for high-altitude nuclear tests in the 1950s and 1960s, and until late in 2000 the atoll was maintained as a storage and disposal site for chemical weapons. Munitions destruction is now complete. Cleanup and closure of the facility was completed by May 2005. The Fish and Wildlife Service and the US Air Force are currently discussing future management options; in the interim, Johnston Atoll and the three-mile Naval Defensive Sea around it remain under the jurisdiction and administrative control of the US Air Force.

Johnston Airfield
Used during the war part of the ferry route form Hawaii to the South Pacific