Operated by United Air Transport as CF-BEP, this Ford Tri-motor flew the first air mail from Edmonton to Whitehorse on July 5, 1937, and then back to Edmonton 3 days later.
For a very detailed history of this aircraft, which is currently being restored, see
fordtri-motor.com.
This photo (location unknown) is in the collection of the Provincial Archives of Alberta - Charles Eymundson fonds, PR2012.0927/164.