Caribou are the only members of the deer family (Cervidae) in which both males and females grow antlers. Males can have massive antlers while those of females are generally much smaller. Caribou are well adapted to their northern environment. Their large, well-insulated hooves prevent sinking when traveling on wetlands and snow and are adapted for digging through snow for food.
Northern mountain caribou are a distinct ecotype of woodland caribou. Woodland caribou are the largest subspecies of caribou in the NWT; males weigh an average of 150 kg and can reach 1.2 m high at the shoulder. Their brown summer coat turns greyish in winter. In all seasons their neck, mane, underbelly, rump and a patch above each hoof are creamy white. Antlers of woodland caribou are thicker and broader compared to those of barren-ground caribou.
Northern mountain caribou are similar to boreal caribou, the other ecotype of woodland caribou found in the NWT, but have different habitat preferences and behaviour. Northern mountain caribou live in the Mackenzie Mountains. Many are migratory and sometimes gather into large groups. They have distinct migrations both in elevation, where they move up or down in response to changes in food quality and availability, and in season, between summering and wintering areas. Seasonal migrations may involve groups of thousands of animals. There is also a non-migratory (sedentary) group of northern mountain caribou that lives in the Sahtu region of the Mackenzie Mountains.