A master reporter’s landmark work of contemporary ecology. The Great Lakes hold 20 percent of the world’s freshwater, and they provide food, work, and weekend fun for tens of millions of Americans. Yet they are under threat as never before. In a work of narrative reporting in the vein of Rachel Carson and Elizabeth Kolbert, prize-winning reporter Dan Egan delivers an eye-opening portrait of our nation’s greatest natural resource as it faces ecological calamity. He tells the story of the St. Lawrence Seaway and the Chicago ship canal—good ideas in their time that have had horrendous consequences. He explains how invasive species such as Asian carp, sea lamprey, and zebra mussels have decimated native species and endanger the entire United States. And he examines new risks, such as unsafe drinking water, the threat of water diversions, and “dead zones” that cover hundreds of square miles of water—while showing how the Great Lakes can be restored and preserved for generations to come.