-As of April 2004, the National Wilderness Preservation System contained 662 wilderness areas totaling 105.7 million acres, or 4.67 percent of all land in the United States.
-There are approximately 43.6 million acres in national parks, 34.8 million acres in national forests, 20.7 million acres in national wildlife refuges, and 6.5 million acres on the western heritage lands of the Bureau of Land Management.
-More than half, or 57.5 million acres, of all designated wilderness is in the huge national parks, wildlife refuges, and forests of Alaska; more than one-third is in the 11 westernmost contiguous 48 states.
Stats: Wilderness Society