Ajo Air Force Station Ajo Air Force Station is a closed United States Air Force General Surveillance Radar station . It is located northwest of Ajo , Arizona . It was closed in 1969 by the Air Force , and the radar site turned over to the Federal Aviation Administration ( FAA ) . Today the site is part of the Joint Surveillance System ( JSS ) , designated by NORAD as Western Air Defense Sector ( WADS ) Ground Equipment Facility J - 29A . History . Ajo Air Force Station came into existence as part of Phase III of the Air Defense Command Mobile Radar program . On October 20 , 1953 ADC requested a third phase of twenty - five radar sites be constructed . Ajo was one of the most expensive ADC radar stations to be constructed , with costs mounting to approximately $ 7 . 4 million for 100 structures located within housing , cantonment , operations , ground - air transmitter - receiver ( GATR ) areas . This site became active in January 1958 with the 612th Aircraft Control and Warning Squadron being assigned to the new station under 34th Air Division . Initially , 612th AC & W Squadron operated AN / FPS - 20 A and AN / FPS - 6 radars , and initially the station functioned as a Ground - Control Intercept ( GCI ) and warning station . As a GCI station , the squadron ' s role was to guide interceptor aircraft toward unidentified intruders picked up on the unit ' s radar scopes . The Ground Air Transmitting Receiving ( GATR ) Site for communications was located at , approximately 0 . 8 miles north - northwest from the main site . Normally the GATR site was connected by a pair of buried telephone cables , with a backup connection of dual telephone cables overhead . The Coordinate Data Transmitting Set ( CDTS ) ( AN / FST - 2 ) at the main site converted each radar return into a digital word which was transmitted by the GATR via microwave to the Control Center . During 1961 Ajo AFS joined the Semi Automatic Ground Environment ( SAGE ) system , feeding data to DC - 21 at Luke AFB , Arizona . After joining , the squadron was re - designated as the 612th Radar Squadron ( SAGE ) on 15 October 1961 . The radar squadron provided information 24 / 7 the SAGE Direction Center where it was analyzed to determine range , direction altitude speed and whether or not aircraft were friendly or hostile . On 31 July 1963 , the site was redesignated as NORAD ID Z - 181 . By 1963 an AN / FPS - 7 C had assumed search duties , and height - finder radar chores were being performed by AN / FPS - 6 A and AN / FPS - 26 radars . On 31 July 1963 , the site was redesignated as NORAD ID Z - 181 . In addition to the main facility , Ajo operated an AN / FPS - 14 Gap Filler site : The 612th Radar Squadron was inactivated on December 31 , 1969 . Housing units were moved to Gila Bend , and the remaining buildings were abandoned . After the site ' s closure , the buildings and other structures of the former Ajo AFS sat abandoned and deteriorated for decades . Today , all buildings and structures of the original Air Force Station , except for the AN / FPS - 26 height - finder radar tower , are now gone . The National Park Service demolished the station site in 1994 and restored it to its natural state . Even the concrete pads for the buildings have been removed . A minimal Air Force and FAA presence was kept to operate some instrumentation and radio - signal relay equipment . The radar site has since re - opened as a Joint Surveillance System ( JSS ) FAA facility ( J - 29A ) replacing the JSS site at Humboldt Mountain ( Phoenix ) , AZ . It operates an ARSR - 4 radar and a communications site for the Barry M . Goldwater USAF Range ( formerly known as Luke - Williams Range ) . The former Air Force radar site also hosts an Air Combat Maneuvering Instrumentation ( ACMI ) antenna on top of old AN / FPS - 26 radar tower . Air Force units and assignments . Units : Assignments :