Yellowstone National Park Report
Records of backcountry use in Yellowstone National Park indicate that use increased from 16,767 backcountry camper nights in 1971 to 33,297 backcountry camper nights in 1974, a doubling in three years (1). A similar increase was recorded in Grand Teton National Park. Use of wilderness areas in the state by backpackers has increased also, but not at the rate of increase that applies to the two National Parks.
Phillips, Clynn; Eastwood, John; and McDonald, Lyman
"A Study of Backcountry use within Yellowstone National Park,"
University of Wyoming National Park Service Research Center Annual Report: Vol. 2
, Article 27.
Available at: http://repository.uwyo.edu/uwnpsrc_reports/vol2/iss1/27