It established 9.1 million acres of wilderness areas on the national forests. In simple, almost poetic language, the Wilderness Act defines the goals and principles behind the National Wilderness Preservation System, which now includes nearly 100 million acres in 546 areas on national forests, national wildlife refuges, national parks and Bureau of Land Management lands. As a rule, human activities are restricted to those that leave no long-term impact on the ground, or that have little or no effect on the natural resources of the area. Human access by primitive means is permitted.
People can enter wilderness areas by foot, on horseback or by nonmotorized boats.
Mechanized access is not allowed, meaning mountain bikes as well as ATVs are prohibited. Wheelchairs are the only mechanized form of access permitted in wilderness areas. The use of aircraft is allowed under special permits. For example, outfitters are allowed access to several airstrips in Idaho's River of No Return Wilderness, and helicopters are frequently used by wildlife agencies to manage wildlife. The Utah Division of Wildlife Resources uses low-level flights to stock fish by air in the High Uintas Wilderness Area.