High in the mountains-over 10,000 ft in altitude, an unusual protagonist takes center stage: the white bark pine. This odd-looking tree may not seem like much, but it is the giver of life not only on high but also to everything below. We explore life at the highest altitudes, profiling the animals who rely on the tree for protection or sustenance: the grizzly bear, Clark's nutcracker, red squirrels, and bighorn sheep.