The latest info I've been able to dig up from aviators that have been flying in my province for many decades about this aircraft.
This Beech 18 belonged to the US Airforce, which was enroute to Flin Flon, Manitoba (CYFO), from (sorry,can't remember which US airport)
I don't have a date, but would have been LONG before the Key Lake, SK minesite was there. They got lost and ran out of fuel, with 4 or 5 people onboard. They'd been there for 4 or 5 days before they were found by a Trapper that had seen footprints and followed it to the crash site.