From timberline (about 11,500 feet) up to our highest Colorado mountain summit (Mt. Elbert 14,431 feet) climate is too severe for any trees. This condition marks these areas off as a separate life zone called Alpine or Arctic. Soil forms only slowly on these rocky summits, but mosses, lichens, sedges and grasses have been here for ages of time, all of them patiently building humus. Erosion carries less soil away from the tops than it does from the lower hillsides. So in the spaces between the barren looking rocks, good soil exists, and water, though mainly falling as snow, and not quite as heavily as in the sub-alpine zone below, is adequate for plants. Here grasses, sedges, a few dwarf shrubs and herbaceous plants have all the sunlight to themselves without tree competition. The ever-present adverse condition is low temperature, frequently with strong wind.

It is a land of tough dwarf things. Perennials are the rule, though annuals are found. Low woody mats with basal leaves and flowers only a few inches high are a common pattern. Bulbs and tubers wedge themselves between rocks, out of reach of ground squirrels, if possible. When spring comes with a rush, usually late in June, these dormant plants burst into life in the days of longest sunshine. Shoots of new growth erupt from the ground with buds all formed ready to open. By the end of July the seed crop is largely mature, and by mid-August the browns and crimsons of fall colors in leaves and grasses spread a Persian carpet over these heights. Warm days from then till winter are days of germination for newly scattered seeds and, for established plants, preparation of buds for next year.

It is in this zone of harsh living conditions that some individual plants probably attain greater age than is normally reached by plants of the lower life zones. We know of no statistical study to support this statement, but observation of mats of moss campion, or of tufts of alpine spring beauty, or of scarred old crowns of alpine forget-me-not, indicates that they have safely survived the snow cover of a great many alpine winters.

The view at the top of this page is from Trail Ridge in Rocky Mountain National Park. Longs Peak is in the distance. In mid-July these foreground slopes are a garden of alpine flowers.