<P>The Appalachian Trail, a thin ribbon of wilderness running through the densely populated eastern United States, offers a refuge from modern society and a place apart from human ideas and institutions. But as environmental historian—and thru-hiker—Sarah Mittlefehldt argues, the trail is also a conduit for community engagement and a model for public-private cooperation and environmental stewardship.</P><P>In <I>Tangled Roots</I>, Mittlefehldt tells the story of the trail’s creation. The project was one of the first in which the National Park Service attempted to create public wilderness space within heavily populated, privately owned lands. Originally a regional grassroots endeavor, under federal leadership the trail project retained unprecedented levels of community involvement. As citizen volunteers came together and entered into conversation with the National Parks Service, boundaries between "local" and "nonlocal," "public" and "private," "amateur" and "expert" frequently broke down. Today, as Mittlefehldt tells us, the Appalachian Trail remains an unusual hybrid of public and private efforts and an inspiring success story of environmental protection.</P>