At the juxtaposition of earth and sky, the mountain goat is master of one of the world's toughest domains, the high Rocky Mountains of North America. In order to survive it must push the limits, to the highest and steepest corners of its insecure realm. How do the goats come by such mastery of rock and ice? Dense fur and guard hairs, specialized hoofs, and uncommon balance give them the means to thrive where others fear to tread.

No other large American animal can negotiate the heights like a goat. And they seem inherently aware of this, with a climber's confidence that approaches cockiness. They will even stare down predators, as long as there is a wall or cliff handy. Short legs, muscular shoulders, and padded hoofs with flexible toes give these mountaineers the strength and balance to defy gravity and enemy.

Few people ever see a wild goat. If they do it's a lucky glance from the window of a car or while hiking in an alpine meadow, among wildflowers in summertime. The real world of the mountain goat is simply too inhospitable for humans. (Next photo)