Snow Treasure (1968)

Based on a children's novel by Marie McSwigan, Snow Treasure tells the story of Norwegian children smuggling gold from Norway's national treasury to keep it out of the hands of the occupying army of Nazi Germany. Young Peter Lundstrom and his sister smuggle the gold one bar at a time by skiing from the mountains to his uncle Oyen, a member of the Resistance, who spirits it away on a fishing boat. But with winter coming to an end, the children must ski all day every day to accomplish their mission.
Although top billed, James Franciscus has a minor role as Second Lieutenant Kalasch, a Nazi soldier who discovers what the children are doing but instead of reporting them, decides to help them.