Caribou occur throughout the boreal and sub-alpine forests and tundra regions of the Northern Hemisphere. They live in the most severe environmental conditions and occupy the most restrictive northern most niches of the world. All Caribou and reindeer throughout the world are considered to be the same species, with seven sub-species. In Canada there are three Sub-species, Barren Ground caribou, Peary Caribou and Woodland Caribou ( Mountain Caribou).

        Peary Caribou are smaller and lighter in color than the Barren Ground Caribou. They have a shorter faces and legs. Peary Caribou are only found on the islands of Canada's far north.

        Barren Ground Caribou occupy the far Northern boreal forests and arctic tundra in Alaska, Yukon and Northwest Territories.

        Woodland Caribou are found east of the Coast mountains, to the foothills of the Rocky mountains. Woodland Caribou are classified into three ecotypes,Mountain Caribou, Northern Caribou and Boreal Caribou.

        In the summer the coat is brown or grayish-brown above and lighter below, with white along the lower sides of the tail and hoof edges. The winter coat is much lighter, with dark brown or grayish brown areas on the upper part of the head, on the back, and on the front of the limbs. A thick white coat of hollow hair provides good insulation from the Arctic climate. Caribou have large crescent shaped hooves and the tracks have a distinct imprint of a dew claw, which provides additional support in the snow. Both sexes have erect spread antlers, however the bulls are much larger. Two tines come off the front of each main antler beam, one lower brow tine on the bull is palmate near the tip, and is used to push snow aside while they feed. All other tines come off the back over the shoulders. Caribou are a medium sized member of the deer family. Weight varies with subspecies, sex and location ranging form 200lbs(91kg) to 594lbs(270kg)

        Caribou are typically grazers. Grass, sedge, mosses, forb, mushrooms and lichen make up the summer diet. In winter the Caribou eat the buds, leaves and bark of both deciduous and evergreen shrubs, and also lichens. Lichen is the most important food source for for all Woodland Caribou.  Mountain Caribou live in areas with snow too deep to dig through and depend on the tree lichen of old growth forest for up to eight months of the year.