National wildlife refuges are for a lot more than just the birds. Almost all allow outdoor recreation, from (admittedly) bird-watching to extended wilderness trips. National wildlife refuges vary in size from tiny half-acre islands to the huge — and embattled — Arctic National Wildlife Refuge. Other gems of the system include Georgia's lush Okefenokee Swamp, Alaska's Kenai NWR, and Montana's National Elk Refuge.

Refuges are managed for wildlife, and many times that means activities happen that would be unacceptable in areas managed for scenic preservation, such as national parks. Dams might manage water levels for waterfowl breeding. Or millet and other grain crops might be sown, much like a farm field, for feeding birds. However, one of the best-kept secrets is that national wildlife refuges harbor more than 90 million acres of wilderness. Wilderness highlights in the refuge system include Arizona's Cabeza Prieta and New Jersey's Great Swamp.

National wildlife refuges are administered by the Fish and Wildlife Service (FWS). The FWS is charged with protecting fish, plants, wildlife, and their habitats, as well as enforcing the Endangered Species Act.