Tucked in a valley of the Cherokee National Forest, on the border of Tennessee, North Carolina, and Georgia, Ducktown once reflected the beauty of the surrounding Appalachian Mountains. Instead, Ducktown and the valley known as the Copper Basin now form the only desert east of the Mississippi. Mined for its rich copper lode since the 1850s, it had become a vast stretch of lifeless, red-clay hills. It was an early and stark lesson in the devastation that acid rain and soil erosion can wreak on a landscape, one of the few man-made landmarks visible to the astronauts who landed on the moon.

Prospectors came to the basin during a gold rush in 1843, but the closest thing to gold they discovered was copper, and most went home. But by 1850, entrepreneurs realized the value of the ore, and a new rush began to mine the area. Within five...