On January 25, 1957, the Department of Treasury was granted a 5-year permit for the United States Coast Guard (USCG) to operate and maintain a Long Range Aid to Navigation (LORAN) transmitting station on Johnston Atoll. Two years later in December 1959, the Secretary of Defense approved the Secretary of the Treasury's request to use Sand Island for U.S. Coast Guard LORAN A and C station sites. The USCG was granted permission to install a LORAN A and C station on Sand Island to be staffed by U.S. Coast Guard personnel through June 30, 1992. The permit for a LORAN station to operate on Johnston Island was terminated in 1962. On November 1, 1957, a new United States Coast Guard LORAN-A station was commissioned. By 1958, the Coast Guard LORAN Station at Johnston Island began transmitting on a 24-hour basis, thus establishing a new LORAN rate in the Central Pacific. The new rate between Johnston Island and French Frigate Shoals gave a higher order of accuracy for fixing positions in the steamship lanes from Oahu, Hawaii, to Midway Island. In the past, this was impossible in some areas along this important shipping route. The original U.S. Coast Guard LORAN-A Station on Johnston Island ceased operations on June 30, 1961 when the new station on nearby Sand Island began transmitting using a larger 180 foot antenna.
The LORAN-C station was disestablished on July 1, 1992, and all Coast Guard personnel, electronic equipment, and property departed the atoll that month. Buildings on Sand Island were transferred to other activities. LORAN whip antennas on Johnston and Sand Islands were removed, and the 625-foot LORAN tower and antenna were demolished on December 3, 1992. The LORAN A and C station and buildings on Sand Island were then dismantled and removed.
