Cold River.

Based on the novel Winterkill, by William Judson, Cold River is the story of an Adirondack guide who takes his young daughter and step-son on a long camping trip in the fall of 1932. When winter strikes unexpectedly early (a natural phenomenon known as a 'winterkill' - so named because the animals are totally unprepared for a sudden, early winter, and many freeze or starve to death), a disastrous turn of events leaves the two children to find their own way home without food, or protection from the elements.