wilderness, land retaining its primeval character with the imprint of humans minimal or unnoticeable. In the United States, the Wilderness Act of 1964 established the National Wilderness Preservation System with a nucleus of 9 million acres (3.6 million hectares) of land in 54 different areas, mostly in Western states, and provided for the designation of new wilderness areas. By 1992, the total had risen to 95 million acres (38.4 million hectares) in 708 parcels of land. Alaska, with 57.6 million acres (23.3 million hectares), was by far the leading repository of wilderness; Ohio had but 77 acres, and some states had none, although designated areas included several Eastern locations where signs of civilization were substantially erased. Wilderness lands are to be preserved in their natural condition, wild and undeveloped, both for their own sake and for humankind's solitude and enjoyment of their beauty. The idea of wilderness has deep roots in American thought (see environmentalism). In the 17th cent. William Penn decreed that one acre of forest be left wild for every five that were cleared. Henry David Thoreau believed that the existence of wilderness was justified by the inspiration people could draw from it.
See P. Brooks, The Pursuit of Wilderness (1971); R. Nash, Wilderness and the American Mind (3d ed. 1982).