The area around Glacier Bay in southeastern Alaska was first proclaimed a U.S. National Monument on February 25, 1925. It was changed to Glacier Bay National Park and Preserve on Dec. 2, 1980 by the Alaska National Interest Lands Conservation Act. Glacier Bay National Park and Preserve is a United States National Park in the southeastern part of Alaska west of Juneau. The park area was included in an International Biosphere Reserve in 1986 and is part of a UNESCO World Heritage Site. The park covers 5,130 mi² (13,287 km²). Most of the park is a designated wilderness area which covers 4,164 mi² (10,784 km²) of the park.