The yak is a shaggy-haired, hoofed animal found in Tibet and parts of China, surviving as high as 20,000 feet in the Himalayans, in temperatures as low as -40 degrees Celsius. The yak was domesticated some 5,000 years ago and is kept primarily for its milk, fur fibers, and meat, as well as to pull loads and plow fields. Butter made of yaks' milk is mixed with tea leaves and salt to make yak butter tea, a traditional Tibetan drink served to guests.