Snow Treasure (1968) on Netflix

Plot summary

It is the winter of 1940, and German forces have invaded Norway, occupying the coastal fishing village of Riswyk. Peter Lundstrom, thirteen, wants to join his father, Lars, and his uncle, Victor, in the fight. In a cave, Peter finds gold bars, and Victor tells him the mission: the gold must reach his fishing boat and be carried overseas to buy munitions. German soldiers search adults at checkpoints but never stop children, and Peter and his friends spend their days on cross-country skis. One bar each per trip, the children begin carrying the gold down to a clearing. They have until the spring thaw, when the melting snow would end the skiing and expose the hidden cave.