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Noatak National Preserve is a United States National Preserve in northwestern Alaska that was established to protect the Noatak River Basin. The Noatak River system, located just north of the Arctic Circle, is thought to be the last remaining complete river system in the United States that has not been altered by human activities. The roadless basin was proclaimed a United States National Monument in 1978 and a National Preserve in 1980 through the passage of the Alaska National Interest Lands Conservation Act (ANILCA). Noatak National Preserve borders Kobuk Valley National Park on the south and borders Gates of the Arctic National Park on the east. Unlike the national parks that it borders, sport hunting is allowed in Noatak National Preserve. ==Ecology and geology== The preserve includes the transition zone from boreal forest to tundra near the southern edge of the preserve. The Noatak Basin is a transition zone for plants and animals between Arctic and subarctic environments. The lower portion of the Noatak valley has areas of boreal forest, but most vegetation is low-growing tundra species. Alpine tundra occurs at high elevation, and moist tundra, the most common condition, supports cottongrass, willows, Labrador tea, mountain alder, dwarf birch and other tundra species at lowr elevations. Boggy areas support cranberry, bog rosemary and salmonberry.〔 Wildlife of the Noatak tundra includes moose, grizzly bears, black bears, wolves, Arctic foxes, lemmings, Dall's sheep, vast herds of caribou numbering more than 230,000 individuals, and a variety of birds. Larger birds include Canada geese, tundra swans, white-fronted geese and common, Arctic, yellow-billed and Pacific loons. Predatory birds include rough-legged hawks, gyrfalcons and golden eagles.〔(【引用サイトリンク】url=http://www.nps.gov/akso/akarc/cr_noat.htm )〕 The central feature of the preserve is the Noatak River, and is a breeding ground for a variety of commercially important fish. The most widespread salmon species is chum, and pink, chinook and sockeye salmon are found as well. Several kinds of trout are fund in deep lakes, with Arctic char and Arctic grayling the most common salmonids in the preserve. Burbot are also found, as are nelma or sheefish, an important species for subsistence fisheries.〔 The Brooks Range has existed since Cretaceous time, and is composed mainly of shales, limestone and chert, with intrusions of igneous rocks from more recent volcanism. The valleys are composed of limestone, sandstone and siltstone, with deposits of sand, gravel, silt and clay. During the Wisconsonian glaciation the area as incompletely covered by ice, with higher regions glaciated. Permafrost exists in higher regions, becoming patchy at lower levels.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Noatak National Preserve」の詳細全文を読む スポンサード リンク
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