McPhee’s trick here is simple and mean. He takes David Brower, the head of the Sierra Club and the most effective conservationist alive, and drops him in the field with three men who want to use the land, one at a time, then writes down what happens. First a mining geologist who sees copper in the Glacier Peak Wilderness. Then a resort developer, the man who built Hilton Head, walking Cumberland Island in Georgia. Then the big one: Floyd Dominy, commissioner of the Bureau of Reclamation, the dam builder himself, sharing a raft with Brower down the Colorado through the Grand Canyon. They drink Dominy’s beer and argue for days about whether the river should be flooded. Brower had traded away Glen Canyon years earlier to save Dinosaur, and he never got over it. McPhee mostly shuts up and lets them talk.