Alpine Tundra | Nature of America

Alpine tundra begins above the tree line (upper limit of tree growth) in high mountain areas such as the Rockies. In this environment, snow covers much of the landscape until spring, and temperatures can be chilly even in summer.

To survive here, plants grow close to the ground and have extensive root systems that absorb water, collect nutrients, and anchor them against the wind. Only the hardiest animals live year-round on the tundra. In summer and fall they build up body fat and, in some cases, store food in dens or burrows. As the weather grows colder, thick fur or feathers help keep them warm. Some hibernate through winter.

The stamp pane depicts a summer scene in Rocky Mountain National Park, Colorado, where snow lingers on the highest slopes and in a few sheltered basins. Elk and bighorn sheep graze the open areas while small mammals find safety amid the rocks. Birds