I was checking out the top search results on Google for "Sioux Lookout" when I came across a site dedicated to the old Pinetree Line.  It was a series of radar sites setup in the early 50's by the US Airforce and later taken over by the Canadian Armed Forces.  It contains a number of old photos from the base and of the area around Sioux Lookout.  Check it out if you are interested in history or are from the area.