Glacier Bay Basin in
southeastern Alaska, in the
United States, encompasses the Glacier Bay and surrounding mountains and glaciers, which was first proclaimed a U.S. National Monument on February 25, 1925, and which was later, on December 2, 1980, enlarged and designated as the Glacier Bay National Park and Preserve under the Alaska National Interest Lands Conservation Act, covering an area of 3,283,000 acres (1,329,000 ha). In 1986, UNESCO declared an area of 57,000 acres (23,000 ha) within a World Biosphere Reserve. This is the largest
UNESCO protected biosphere in the world. In 1992, UNESCO included this area as a part of a World Heritage site, extending over an area of 24,300,000-acre (98,000 km
2) which also included the Wrangell-St. Elias National Park, Kluane National Park (Canada) and Tatshenshini-Alsek Park (Canada). Part of the National Park is also designated a Wilderness area covering 2,658,000 acres (1,076,000 ha).