In Wide Rivers Crossed , Ellen Wohl tells the stories of two rivers—the South Platte on the western plains and the Illinois on the eastern—to represent the environmental history and historical transformation of major rivers across the American prairie. Wohl begins with the rivers’ natural histories, including their geologic history, physical characteristics, ecological communities, and earliest human impacts, and follows a downstream and historical progression from the use of the rivers’ resources by European immigrants through increasing population density of the twentieth century to the present day. During the past two centuries, these rivers changed dramatically, mostly due to human interaction. Crops replaced native vegetation; excess snowmelt and rainfall carried fertilizers and pesticides into streams; and levees, dams, and drainage altered distribution. These changes cascaded through networks, starting in small headwater tributaries, and reduced the ability of rivers to supply the clean water, fertile soil, and natural habitats they had provided for centuries. Understanding how these rivers, and rivers in general, function and how these functions have been altered over time will allow us to find innovative approaches to restoring river ecosystems. The environmental changes in the South Platte and the Illinois reflect the relentless efforts by humans to control the distribution of water: to enhance surface water in the arid western prairie and to limit the spread of floods and drain the wetlands along the rivers in the water-abundant east. Wide Rivers Crossed looks at these historical changes and discusses opportunities for much-needed protection and restoration for the future. "This intriguing book will quickly capture reader interest with its coverage of the natural history and ecology of shortgrass, and formerly, tallgrass prairie rivers; the effects of subtle to flagrant manipulation of riverscapes and watersheds; and future scenarios for recovery of continued degradation . . . . Valuable for the the educated lay public, environmental scientists, and students, especially those interested in rivers and human impacts. Highly recommended." ―J. H. Thorp III, Choice "But the value of Wohl's work lies in her assertion that we have as much potential for the (re)creation of healthy ecosystems as we do for the destruction of these systems. Too many environmentally-minded books focus on the destructive power of human actions without pointing the way towards what can be done to mitigate and reverse our detrimental influence..." -Sara Porterfield, Annals of Wyoming  Ellen E. Wohl teaches geology at Colorado State University and is the author of seven other books, most recently Island of Gras s (UPC). Wide Rivers Crossed The South Platte and the Illinios of the American Prairie By Ellen Wohl University Press of Colorado Copyright © 2013 University Press of Colorado All rights reserved. ISBN: 978-1-60732-230-6 Contents Prologue, PART I. STREAMS OF THE SHORTGRASS PRAIRIE: THE SOUTH PLATTE RIVER BASIN, Chapter 1. At the Headwaters, Chapter 2. Onto the Plains, Chapter 3. River Metamorphosis, Chapter 4. What the Future Holds, PART II. STREAMS OF THE TALLGRASS PRAIRIE: THE ILLINOIS RIVER BASIN, Chapter 5. Natural History of the Illinois River, Chapter 6. Native Americans and the First European Settlers, Chapter 7. Twentieth-Century River Metamorphosis, Chapter 8. What the Future Holds, Epilogue, English-Metric Unit Conversions, Selected Bibliography, Index, CHAPTER 1 At the Headwaters Crossing the summit of an elevated and continuous range of rolling hills, on the afternoon of the 30th of June we found ourselves overlooking a broad and misty valley, where, about ten miles distant, and 1,000 feet below us, the South fork of the Platte was rolling magnificently along, swollen with the waters of the melting snows. It was in strong and refreshing contrast with the parched country from which we had just issued; and when, at night, the broad expanse of water grew indistinct, it almost seemed that we had pitched our tents on the shore of the sea. — John Charles Frémont, on reaching the base of the Colorado Rockies after traveling westward across the Great Plains, June 1843 SNOWFALL In much of the world, a flowing river represents the excess water that cannot be held by the plants and soil along the river's course. The adjacent landscape overflows into the river, each tributary swelling the flow of the mainstem. In contrast, the stream flow that sustains the largest rivers of the western prairie begins far from the dry lowlands, and tributaries heading on the prairie contribute little to the mainstem. This is one of the paradoxes of rivers of the western prairie: flowing for hundreds of kilometers across some of the continent's driest and most open country, the rivers begin in, and are sustained by, abundant winter snows falling in deep, narrow valleys of the