On an uninhabited island off the coast of Southern California where pygmy mammoths once roamed, I trekked along sandstone cliffs and up a steep footpath into one of the rarest native pine forests in the United States. Dwarfed and gnarled by the fierce winds, the endangered evergreens with freakishly large pine cones were so mesmerizing that I almost missed seeing a fox that is found nowhere else on earth.