national preserve in Alaska, U.S., adjoining Gates of the Arctic National Park to the east and Kobuk Valley National Park to the south. Proclaimed a national monument in 1978, the area underwent boundary and name changes in 1980. The entire area is located north of the Arctic Circle and contains the largest untouched river basin in the United States. Landforms of scientific interest include the Grand Canyon of the Noatak (65 miles 【105 km】 long), a transition zone and migration route for flora and fauna between subarctic and Arctic environments. The preserve has hundreds of archaeological sites, and wildlife includes caribou, grizzly bears, Dall sheep, moose, and wolves, and waterfowl, raptors, and other bird species. The total area is 10,273 square miles (26,607 square km).