The National Wilderness Preservation System has evolved from the first wilderness preserve in 1919 to nealry 89 million acres in 1985. The Forest Service administers 83% of the wilderness system in the conterminous forty-eight states, where most future use is expected. The Wilderness Act of 1964 specifies that wilderness areas are to be administered for the use and enjoyment of the American people, and managed to protect and preserve wilderness qualities. Establishing acceptable levels of wilderness area naturalness and associated levels of human inpact is a fundamental management problem. A user preference concept is proposed to assist in decision making. A working philosphy for implementing Forest Plans to preserve wilderness qualities while allowing humna use incorporates the user preference concept. The Greater Yellowstone Area presents a unique challenge in administering the wilderness resource because some of its parts are in differnt jurisdictions. More than 60% of the Greater Yellowstone Area is designated or proposed as wilderness, and primary dependents are wildlife and recreationists. Management of the area to optimize conditions for human uses while preserving unique wilderness ecosystem resources is progressing through increasing interagency cooperation.