[from the text] Outdoor recreation is continuing to increase in the United States. Hendee et al. (1977) estimated that public use of wilderness areas will increase, in the 40-year period from 1960 to 2000, by nearly tenfold. A report by the Heritage Conservation and Recreation Service (HCRS; 1979) showed rapid growth in such outdoor recreation activities as skiing, snowmobiling, canoeing, and off-road-vehicle use as well as tremendous growth potential in the area of primitive camping. The President's Commission on Americans Outdoors (1987) reported persistent vigorous interest in a broad spectrum of outdoor recreation; for example, there were increases from 1960 to 1982 in canoeing (515%), bicycling (382%), camping (240%), hiking and backpacking (199%), and walking for pleasure (132%). Of the federal land-management agencies, the U.S. Forest Service continues to provide more total visitor time than any other federal agency-approximately 2.5 billion visitor hours in 1984.