Project Blue Book Case #6400. On June 18, 1959, an unidentified object was reported over Edmonton, Alberta — the capital of the western Canadian province and a major city along the northern air defense corridor. Edmonton's position in western Canada placed it directly beneath the flight paths that Soviet bombers would traverse in a polar attack against North America.
Edmonton was home to the RCAF's No. 4 Flying Training School and was near Cold Lake, Alberta — one of Canada's most important military air bases. The city's role in the joint U.S.-Canadian North American air defense system (which would become NORAD in 1958) meant that unidentified aerial reports from the Edmonton area were taken seriously by both Canadian and American military intelligence.
The NORAD corridor through western Canada was one of the most carefully monitored airspaces in the world. Radar stations of the Mid-Canada Line and the Pinetree Line provided overlapping coverage, specifically designed to detect incoming Soviet aircraft. Any object that could not be identified against this comprehensive surveillance picture was, by definition, anomalous.
The Edmonton sighting reached Blue Book through the bilateral intelligence-sharing channels that linked the Canadian and American air defense establishments. No identification could be made. The case was classified "Unknown."