Butter sculpture dates back to ancient Tibet. Carvings were made out of yak butter. The carvings were of animals and religious figures. In the 1800s, the practice spread to the United States. Butter sculpture became popular at state fairs. The Minnesota State Fair features butter sculptures. In 1965, the fair began a new tradition. The state's "dairy queen" was sculpted in butter. Butter sculptures are also a tradition at the Iowa State Fair. Visitors can see butter sculptures of cows. In 2011, the fair celebrated its 100th year of butter cows. Do It! Butter sculpture has a _________ history.