About 20 000 years ago, when most of Canada was covered by ice, herds of muskoxen survived in unglaciated refugia.
The muskox originated in Eurasia, and probably reached North America across the Bering Strait, when lowered sea levels associated with the Illinoian glaciation (150 000 to 250 000 years ago) exposed a land bridge between the two continents.
The muskox (or omingmak, as Inuit call it) is superbly adapted to Arctic conditions by its compact build; thick pelt of long guard hairs and soft undercoat of fine, densely packed hair (or qiviut, as Inuit call it); furry muzzle; well-muffled ears and short tail.
Today's muskoxen are approximately 132 to 138 cm (51 to 54 in.) tall (at the shoulder). Their weight ranges from 260 to 650 kg (572 to 1430 lb.). Muskoxen eat primarily sedges, willows and forbs.
Muskox fossils have been found in Canada (including Alberta, Saskatchewan, Manitoba, Ontario, Yukon, Northwest Territories), the northern United States (including Alaska). Today, muskoxen inhabit Arctic Canada and Greenland, and they have been reintroduced in Alaska and elsewhere.