Gates of the Arctic National Park and Preserve, N Alaska. Located N of the Arctic Circle, the park (7,523,898 acres/3,046,113 hectares) and adjacent preserve (948,629 acres/384,060 hectares) make up the second largest unit of the National Park System. Gates of the Arctic is a tundra wilderness of broad valleys and the razorlike peaks of the Brooks Range, and is known for its abundance of arctic caribou, grizzly bears, moose, and wolves. It was proclaimed a national monument in 1978 and designated a national park and preserve in 1980. Within the park and preserve are the 83-mi (134-km) Alatna Wild River, the 52-mi (84-km) John Wild River, the 110-mi (177-km) Kobuk Wild River, part of the 330-mi (531-km) Noatak Wild River, the 102-mi (164-km) North Fork of the Koyukuk Wild River, and the 44-mi (71-km) Tinayguk Wild River, all of which were authorized in 1980. See National Parks and Monuments (table).