The Pine Tree Line was one of three US-Canadian radar lines across Canada.
Lowther
The Lowther station located 30 miles west of Kapuskasing, Ontario became operational in 1958. Lowther was built and originally manned by the USAF 639th Aircraft Control and Warning Squadron.
Lowther radar station
The cover below was mailed from Lowther when the USAF controlled the station:
Lowther to Trenton, Ont., March 13, 1963
Sign at Lowther Radar Station when operated by USAF
On June 26, 1963, Lowther radar base changed from US to Canadian control becoming RCAF Station Lowther.
Ms. Karrie Emms has written an interesting article about the Lowther Station entitled "Canadian Forces Bases Pine Tree Line".
Lowther was closed on March 31, 1987 and this radar equipment, along with a commemorative plaque, were placed at the west entrance to Kapuskasing:
