Watch Sergeant Preston of the Yukon (1955) Season HD Full Free on solarmovie.do. Watch Sergeant Preston of the Yukon (1955) tv series online free. Canadian Mountie Sgt. Preston patrols the wilds of the Yukon with his horse Rex and his faithful dog...Canadian Mountie Sgt. Preston patrols the wilds of the Yukon with his horse Rex and his faithful dog Yukon King, battling both the elements and criminals.