Prof. Thomson (Botany, Connecticut College) disputes the outsider's arrogant notion that there's nothing between Pittsburgh and Denver, but this scholarly landscape history of the Middle West requires readers with more than a smattering of geology and biology. She traces changes during Pleistocene times, follows regional progressions of forest trees, indicates glacial retreats and lake formations (plus a separate chapter for the Great Lakes), and considers the relationship between prairie grasses and grazers. Some mysteries are diverting (of the animals who crossed the Bering Strait, why did large mammals disappear and small ones survive?) and Thomson's easy characterizations of familiar trees (the adaptability of aspen, the rugged nature of jack pine) are accessible. But altogether the accumulation of detail and the technical content will derail the general reader.