 Johnston Atoll has never had any indigenous inhabitants, although during the late part of the 20th century, there were averages of about 300 American military personnel and 1,000 civilian contractors present at any given time.The primary means of transportation to this island was the airport which had a paved military runway or alternatively by ship via a pier and ship channel through the atoll's coral reef system.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.