The Detroit River International Wildlife Refuge is the only international wildlife refuge in North America. It was established in 2001 and is managed jointly by the United States Fish and Wildlife Service and the Canadian Wildlife Service. It is situated in the heart of a major metropolitan area. Detroit River International Wildlife Refuge is one of over 540 National Wildlife Refuges managed by the U.S. Fish and Wildlife Service within the Department of the Interior. It occupies 7.88 square miles (20.42 km2) of scattered property but has drawn boundaries for further expansion.