The snow capped mountains do not look like Panama. Perhaps one of the Civilian Tri-motors operated in Alaska?
http://joebaugher.com/usaf_serials/1942_4.html
42-79547 Stinson C-91 Model SM.6000A MSN A9110 ser no RX-17 impressed by USAAF in Panama. Removed from service in Sept 1943. Was originally NC15110, listed as going to Tranportes Aereos Gelabert of Panama as RX-17. One source has the plane as hveing been a low-wing Type A