Onion John by 
My Side of the Mountain by
A young boy relates his adventures during the year he spends living alone in the Catskill Mountains including his struggle for survival, his dependence on nature, his animal friends, and his ultimate realization that he needs human companionship.
The Gammage Cup by
A handful of Minnipins, a sober and sedate people, rise up against the Periods, the leading family of an isolated mountain valley, and are exiled to a mountain where they discover that the ancient enemies of their people are preparing to attack.