Wilderness areas are places untamed by humans. The Wilderness Act of 1964 allows Congress to designate wilderness areas for protection to ensure that America’s pristine wild lands will not disappear. Wilderness areas can be part of national wildlife refuges, national parks, national forests or public lands managed by the Bureau of Land Management. The U.S. Fish and Wildlife Service manages more than 20 million acres of designated wilderness in the National Wildlife Refuge System. There are 75 wilderness areas on 63 units of the Refuge System in 25 states. About 90 percent of Refuge System wilderness acreage is in Alaska.