Mica Peak Air Force Station Mica Peak Air Force Station ( ADC ID : SM - 151 , NORAD ID : Z - 141 ) is a closed United States Air Force General Surveillance Radar station . It is located east - northeast of Mica , Washington . It was closed in 1975 by the Air Force , and 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 - 79 . History . Mica Peak Air Force Station was initially part of Phase II of the Air Defense Command Mobile Radar program . The Air Force approved this expansion of the Mobile Radar program on October 23 , 1952 . Radars in this network were designated " SM . " The station was logistically supported by the 9th Air Division at Geiger Field , Spokane , Washington . The station became operational on 1 July 1956 when the 823d Aircraft Control and Warning Squadron was assigned to the new station on 1 July 1956 . The squadron started operating AN / FPS - 20 search and AN / MPS - 14 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 . In 1959 Mica Peak AFS received an AN / FPS - 6 A height - finder radar , and began performing air - traffic - control duties for the Federal Aviation Administration ( FAA ) . During 1960 Mica Peak AFS joined the Semi Automatic Ground Environment ( SAGE ) system , initially feeding data to DC - 15 at Larson AFB , Washington . After joining , the squadron was redesignated as the 823d Radar Squadron ( SAGE ) on 15 July 1960 . The radar squadron provided information 24 / 7 to the SAGE Direction Center where it was analyzed to determine range , direction altitude speed and whether or not aircraft were friendly or hostile . In June 1963 , the SAGE feed was switched to DC - 12 at McChord AFB . In 1962 the search radar was upgraded and redesignated as an AN / FPS - 67 . A year later , an AN / FPS - 90 height - finder radar was added . The AN / MPS - 14 was later retired . On 31 July 1963 , the site was redesignated as NORAD ID Z - 141 . In addition to the main facility , Mica Peak operated several AN / FPS - 14 Gap Filler sites : Over the years , the equipment at the station was upgraded or modified to improve the efficiency and accuracy of the information gathered by the radars . In 1967 the search radar was upgraded to an AN / FPS - 67 B . Routine operations were performed until 1975 when the 823rd Radar Squadron ( SAGE ) was inactivated on 1 July . Although the squadron was inactivated and most of the facility was closed , Mica Peak remained in operation manned by various operating locations / detachments of the 25th Air Defense Squadron at McChord AFB . Circa 1977 the AN / FPS - 90 was converted to an AN / FPS - 116 . The 25th ADS shut down operations on 1 October 1979 . The FAA assumed control of the station on 1 October 1979 , however the Air Force maintained the height - finder radar until 1988 when that radar was retired . Through the mid - 1990s , the FAA continued to operate the AN / FPS - 67B set at this site . That radar was then replaced by an ARSR - 4 in the late 1990s . Mica Peak remains an active Joint Surveillance System ( JSS ) site today .