Before skyscrapers and smokestacks rose across the eastern U.S., elk, bison, wolves, and cougars roamed. Typically imagined as icons of the West, these large mammals are in fact native to what was once a kind of Eden--towering forests in the Northeast, rolling prairies in the Midwest, and cypress swamps in the Deep South. But, in mere decades, industrialization and unregulated hunting brought these emblems of the East to the precipice of extinction; by the 1950s, squirrels were one of the few wild mammals an easterner was likely to encounter. Now, even as the climate and biodiversity crises loom, eastern wildlife are staging an unlikely comeback. Herds of bison graze on Illinois prairies, red wolves lurk in North Carolina's coastal marshes, and abandoned coal mines in Kentucky are now home to thousands of elk. Such rewilding promises to restore balance to eastern ecosystems and return one of the most biodiverse regions in the world to its former luster--but not without controversy.