Mule Deer live in a broad range of habitats - forests, deserts, and brushlands. Mountain populations migrate to higher elevation in warmer months, looking for nutrient-rich new-grown grasses, twigs, and shrubs. Learn more about the Odocoileus hemionus, more commonly known as a Mule Deer, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.