In telling of his relationship with one of America's great gifts to hikers, the Appalachian Trail, Bill Bryson investigates numerous issues pertaining to the environment. He discusses both the extent of America's environmental crisis and some of its causes. He also points out that one is never immune from the social problems endemic throughout the United States, even while hiking through some of the country's most remote and inaccessible wilderness.

In the opening chapter, Bryson gives a variety of reasons for his foray into the woods. The most compelling reason, though, is that "the Appalachians are the home of one of the world's great hardwood forests ... and that forest is in trouble." Acid rain and the gradual warming of the earth's atmosphere both spell doom, Bryson observes, for the delicate ecosystem atop the eastern mountains. Many species of tree are in trouble, and others are already...