Rocky Mountain National Park is a national emblem—its rough mountains whittle out a skyline that captures the American imagination and serves as both defender and passageway to the west. One-third of the park is above timberline, the 14,259-foot flat-topped peak of Longs Peak included, there are 71 peaks here that top out above 12,000 feet. All in all, there is enough snow-capped rock, wind-whipped tundra, and thin air to make a marmot flighty. Trail Ridge Road offers visitors breathtaking views, covering 48 miles between Estes Park on the park's east side and Grand Lake on the west. As it winds across the tundra's hugeness, it reaches its highest summit at 12,183 feet.