The locals call it Denali. The federal government calls it Mt. McKinley. Regardless of the name, it the highest peak in North America. And around it’s peaks, are animals that live in a very extreme environment. One such animal is the ground squirrel. And he faces not only extremes in weather, but in the fear of being lunch for golden eagles, foxes, coyotes, wolves, and the largest of Denali’s mammals, the grizzly. His defenses are deep boroughs in the tundra, and a fur that is a natural camouflage.