As a result of the Cold War and with the expansion of a North American continental air defence system, Sioux Lookout 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.

As a GCI base, the 915th's role was to guide interceptor aircraft toward unidentified intruders picked up on the unit's radar scopes.

Upon hand-over on 1 October 1962, the operating unit was re-designated 39 Aircraft Control and Warning Squadron and the base, RCAF Station Sioux Lookout.

It would no longer guide interceptors but only look for enemy aircraft, feeding data to the Duluth Air Defense Sector SAGE DC-10 Direction Center of the 30th NORAD Region.

Today, the station remains standing, although thought as deserted and apparently unused, it is privately owned and now used as a homestead.

The Sioux lookout AN/FPS 107 antenna can be seen at the communication and electronic branch museum at CFB Kingston east McNaughton side.