CFS Armstrong Canadian Forces Station Armstrong ( ADC ID : C - 15 ) is a closed General Surveillance Radar station . It is located east of Armstrong , Thunder Bay District , Ontario . It was closed in 1974 . It was operated as part of the Pinetree Line network controlled by NORAD . History . Origins . There was military activity in Armstrong during the Second World War . The community was the site of a detachment of the US Army ' s 671st Signal Aircraft Warning Company ( Reporting ) , established to detect an enemy air attack on the locks at Soo Locks in Sault Ste . Marie , Michigan . The site was opened in 1942 and abandoned in 1943 as an attack seemed less likely . It is believed that the facility was situated in the same place as CFS Armstrong and no trace of it remains . Cold War . As a result of the Cold War and with the expansion of a North American continental air defence system , Armstrong was selected as a site for a United States Air Force ( USAF ) radar station , one of the many that would make up the Pinetree Line of Ground - Control Intercept ( GCI ) radar sites . This second period began with construction starting in 1952 and completed in 1954 . The site was originally known as Armstrong Air Station in the early 1950s and it was home to the USAF ' s Air Defense Command ( ADC ) 914th Aircraft Control and Warning Squadron . ADC designated the site " C - 15 " . Initial radars installed were AN / FPS - 3 C , AN / FPS - 502 , AN / TPS - 502 , and an AN / FPS - 6 B set . The squadron initially reported to the 30th Air Division at Willow Run AFS , Michigan . As a GCI base , the 914th ' s role was to guide interceptor aircraft toward unidentified intruders picked up on the unit ' s radar scopes . These interceptors were based at the 29th Air Division at Great Falls ( Malmstrom ) AFB , Montana . The squadron was inactivated on 1 November 1962 . On 1 April 1963 Armstrong AS was connected to the Semi Automatic Ground Environment ( SAGE ) system , and the station became a long - range radar site . It would no longer guide interceptors but only look for enemy aircraft , feeding data to the Duluth Air Defense Sector SAGE DC - 10 Data Center of the 30th NORAD Region at Duluth AFS , Minnesota Later that month , the American station was handed over to the Royal Canadian Air Force and renamed the site as RCAF Station Armstrong . This was part of an arrangement with the United States that came as a result of the cancellation of the Avro Arrow . Canada would lease 66 F - 101 Voodoo fighters and take over operation of 12 Pinetree radar bases . The new radar unit , 38 AC & W Squadron , continued in the early warning role . It would later be known as 38 Radar Squadron . It was also upgraded with the following radars : Popular by virtue of being the only radio station , CFAO began broadcasting from the trailer court on the station in the early 60 ' s with a 10 watt transmitter . It was run by a core of 20 volunteers offering music and news to the station and surrounding area seven days a week on 1450 kilocycles . Armstrong had up to three deHavilland Canada Otters operating from the DOT run airfield at any one time . The Otter Flight ' s duties ranged from logistical support , search and rescue , to " Flying Doctor " services . The " Flying Doctor " service was offered on a weekly and monthly basis to personnel stationed at Pagwa and Sioux Lookout . Medical evacuations were carried out as necessary . Dental services were provided on a bi - monthly visit by a Royal Canadian Army Dental Corps detachment . The station had limited recreational facilities , so hunting and fishing became quite popular , as did snowmobiling . With unification of the Canadian Forces , the facility was renamed Canadian Forces Station Armstrong in 1967 . Improvements in radar technology made the site redundant , and on 1 September 1974 , the main gate at CFS Armstrong was swung shut for good and CFS Armstrong was disbanded on 1 October 1974 . The site was sold to private owners , and today the site sits abandoned behind the main gate . There is much to see for the ghost town hunter as all but a few buildings remain . Several Radar towers are standing and the airfield is now run by the provincial government .