Bootherium is an extinct bovid genus from the middle to late Pleistocene of North America which contains a single species, Bootherium bombifrons. Vernacular names for Bootherium include Harlan's muskox, woodland muskox, helmeted muskox or, bonnet-headed muskox Bootherium was one of the most widely distributed musk ox species in North America during the Pleistocene era. Fossils have been documented from Alaska to California and Texas, Missouri, Oklahoma, Virginia, North Carolina and New Jersey. The species became extinct approximately 11,000 years ago at the end of the last ice age.