The story concerns two grizzled mountain men — Bill Tyler and Henry Frapp — during the dying days of the fur-trapping era. The plot begins when Running Moon runs away from her abusive husband Heavy Eagle and comes across the two seedy fur trappers. The mountain men take her in, unaware that Heavy Eagle has dispatched an army of Indian braves to reclaim her.

Marriage takes a sour turn when a middle-aged husband falls for a young and sexy woman. Things get even more complicated when his wife starts a hot affair with a young lover of her own.