Drawing from the field work of hundreds of scientists as well as her own observations, Audrey Benedict describes the geography of the region, its fascinating geologic story, its climate and weather, and its plant and animal communities. The region's major ecosystems, from the shortgrass prairie and scrublands to woodlands and forests, grasslands and meadows, wetlands and aquatic environments, and finally alpine tundra, are described in detail. The emphasis throughout is on the unique adaptations of the major species of plants, mammals, birds, reptiles, and amphibians and how these organisms interact within their environment.