Hulahula Valley, Arctic NWR, Alaska, USA Photograph by US Fish and Wildlife Service   Northwestern North America: Northern United States (Alaska) into western Canada Tundra   61,600 square miles (159,500 square kilometers) -- larger than Georgia Relatively Stable/Intact

· Mountain Continuum
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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Mountain Continuum

This ecoregion is composed of three large areas: the Western Brooks Range, with low, less rugged mountains and less permanent ice; the Eastern Brooks Range/British Range, with higher, more rugged terrain and more permanent ice; and the low Anaktuvuk Pass that separates the two mountainous zones. The strong winds of the major mountain passes are extremely cold. Glaciation, frost, and erosion of steep slopes keep soil from accumulating. Due to the harsh, mountainous terrain and climate of this ecoregion, vegetation cover is sparse and restricted mostly to valleys and lower slopes. Lichens are common and widespread.

Special Features

The eastern Brooks Range supports the northernmost breeding populations of golden eagles and gyrfalcons in the United States. Also, white spruce occurs in the British-Richardson Mountains at the highest latitudinal limit of tree growth in Canada.

	Arctic ground squirrels are some of the few true hibernators of the Arctic. These rodents will go to great trouble to create burrows for shelter. They are seed lovers and will also feed on the ground plants of this ecoregion, such as sedges and cottongrass.

Wild Side

High-elevation alpine tundra consists of lichens, mountain-avens, dwarf heath shrubs, sedge, and cottongrass in wetter sites. Stunted white spruce, occasional alpine fir, and lodgepole pine with willow, dwarf birch, and north Labrador tea form the subalpine open woodlands of middle elevations. The Brooks and British Ranges straddle the migration routes of the Porcupine, Central Arctic, and Western Arctic caribou herds, which generally migrate north and south, following river valleys. The ecoregion is also essential for the seasonal movement of grizzly bears and wolves. Smith's longspurs, horned larks, Dall's sheep, snowshoe hares, red foxes, and Arctic ground squirrels live in this area.

Cause for Concern

The ecoregion is almost entirely intact. But two major highway corridors cross the ecoregion, the Dalton Highway with a parallel oil pipeline, and the Dempster Highway. These roadways can act as a barrier or a filter to the movement of species such as caribou, which have historically migrated alongside the Dalton Highway and pipeline. The highways provide access for hunters, who hunt along the road corridors. Some mineral exploration and extraction has occurred, and mining presents a major future threat. The Red Dog lead-zinc mine, on the western edge of the area, is the largest development in the ecoregion. Vehicles can severely damage tundra. Global warming is an increasing threat with potentially severe impacts in the Arctic.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.