For five million years the Colorado has carved some of the most majestic landscapes on the planet. It has also become the lifeline of a vast portion of North America, providing the water that sustains nearly forty million people, half a dozen major cities, and an immense agricultural empire. Because of these demands, the river is so overused and over promised that it no longer flows to the sea or nourishes its delta. Placing the ecology of the river within a rich social context, The Colorado journeys through the prehistoric settlement of the region, the period of European exploration, the dam-building era, modern industrial agriculture and immigration, and the impacts of climate change.