Brooks Range - Ecology

Ecology

This mountain range forms the northernmost drainage divide in North America, separating streams flowing into the Arctic Ocean and the North Pacific. The range roughly delineates the summer position of the Arctic front. It represents the northern extent of tree line, with few trees (apart from some isolated Balsam poplar stands) occurring north of the continental drainage divide. The southern slopes of the Brooks Range have some cover of Black Spruce, Picea mariana, and Quaking Aspen, marking the northern limit of those trees. As one of the most remote and least-disturbed wildernesses of North America, the mountains are teeming with wildlife, including Dall sheep, grizzly bears, and caribou.

In Alaska, the Western Arctic Caribou herd traverses the Brooks Range in its annual migration. This herd was measured at 490,000 animals in 2004. The smaller Central Arctic herd (32,000 in 2002), as well as the 123,000 strong Porcupine Caribou herd likewise travel through the Brooks range on their migratory paths in and out of the Arctic National Wildlife Refuge. The migration path of the Porcupine Caribou Herd is the longest of any terrestrial mammal on earth.