View of wilderness landscape in Alaska. Photo courtesy of Kennan Ward

Wilderness Preservation Act, U.S.A. The Wilderness Preservation Act, passed in 1964, established the National Wilderness Preservation System and set forth criteria for designating lands for inclusion in this system. According to the Act, wilderness must have the following characteristics: absence of significant human impact; opportunities for solitude and primitive recreation; a size of at least 5,000 acres; and outstanding ecological, geological, or scenic value. Wilderness status protects an area from the building of roads and dams, timber cutting, the use of motorized vehicles, and new livestock-grazing and mining operations. There are presently about 475 wilderness areas, covering 104 million acres. Yet this represents only 4 percent of the United States land area, and two-thirds of this designated wilderness lies in Alaska. 1 of 3