When we look at any living organism, whether it is plant, herbivore, carnivore, parasite, scavenger, or decomposer, we are soon made aware of its associations with other living things, each puzzle piece leading us to another and another. We begin to see a picture whole—the fox, meadow mouse, grasshopper, bunchgrass, and sparrow hawk—all interlocked. Geologically speaking, grasslands are a recent development. As the Rocky Mountains were being uplifted, the prevailing warm, moist climate began to change. The rising mountain mass intercepted moisture-laden winds that blew in from the Pacific, creating a rain shadow that lengthened eastward as the mountains rose higher. A continental climate, characterized by severe winters and dry, wildfire summers gradually took shape, extinguishing the great forests that had grown across the continent’s interior. Herbaceous plants, which had been evolving amid the forests, inherited the land. Unlike trees, grasses die back to the ground each winter, hoarding their life-germ beneath the protecting soil. Growing not from the tip but from the joints, grasses regenerate quickly after fire or grazing. Suspension of the normal metabolic processes enable the grasses to go dormant and thus survive periods of severe heat and drought. Although the great prairie sea washes up against Glacier’s eastern boundary, with estuaries probing into the mountain valleys on the drier, south-facing slopes, the grassland community comprises less than 5 percent of the land area of Glacier National Park. This includes the puddles of prairie west of the Divide that interrupt the dense coniferous forests along the North Fork of the Flathead River. From the pasqueflowers that bloom in early May to the asters and goldenrod of September, these summer-long gardens of grasses and flowers lean with the wind. Here are timothy, oatgrass and the bunchgrasses—rough fescue, bluebunch fescue, and bluebunch wheatgrass. Among the grasses bloom bitterroot, blue camas, lupine, gaillardia, balsamroot, cinquefoil, sticky geranium, and wild rose. _continued on p. 68_ [Illustration: The Forests of Glacier From the lush redcedar-hemlock forest in the McDonald Valley to the subalpine fir, whitebark pine, and Engelmann spruce struggling for existence near treeline, the forests of Glacier reflect the conditions of temperature, exposure, soil, and drainage prevailing; and each forest has its characteristic association of understory trees and shrubs, herbaceous ground cover, and vertebrate and invertebrate animal life.] [Illustration: Life Zones Many physical and climatic factors determine the range of Glacier’s plant-and-animal communities. Boundaries between communities are seldom sharply defined, but rather merge together in broad zones of transition.