The Brooks 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 the tree line, with little beyond isolated balsam poplar stands occurring north of the continental drainage divide.
Trembling aspen and white spruce also occur north of the Brooks Range, though they are limited to sites that have been disturbed by human activity.
Southern slopes have some cover of black spruce, Picea mariana, marking the northern limit of those trees.
As the global mean temperature increases, tree line has been observed to move further north, changing the boundaries of where these trees are found.
An increase in shrub abundance is also being experienced in areas which were previously dominated by tundra, impacting the ecology of the area.

As one of the most remote and least-disturbed wildernesses of North America, the mountains are home to Dall sheep, grizzly bears, black bear, gray wolf, moose and porcupine caribou.

In Alaska, the Western Arctic Caribou herd (490,000 strong in 2004) traverses the Brooks Range in its annual migration.
 The smaller Central Arctic herd (32,000 in 2002), as well as the 123,000 animal Porcupine Caribou herd, likewise migrate through the Brooks range on their annual journeys 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.
The Brooks 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 the tree line, with little beyond isolated balsam poplar stands occurring north of the continental drainage divide. Trembling aspen and white spruce also occur north of the Brooks Range, though they are limited to sites that have been disturbed by human activity. Southern slopes have some cover of black spruce, Picea mariana, marking the northern limit of those trees. As the global mean temperature increases, tree line has been observed to move further north, changing the boundaries of where these trees are found. An increase in shrub abundance is also being experienced in areas which were previously dominated by tundra, impacting the ecology of the area.
As one of the most remote and least-disturbed wildernesses of North America, the mountains are home to Dall sheep, grizzly bears, black bear, gray wolf, moose and porcupine caribou.
In Alaska, the Western Arctic Caribou herd (490,000 strong in 2004) traverses the Brooks Range in its annual migration.  The smaller Central Arctic herd (32,000 in 2002), as well as the 123,000 animal Porcupine Caribou herd, likewise migrate through the Brooks range on their annual journeys 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.
Brooks Range