Apple Butter Makin' Days, one of Missouri's most popular festivals, has been held on the courthouse square in Mt. Vernon each October since 1967. The main attraction is apple butter, cooked using century-old methods in huge copper kettles over open fires. That craft is demonstrated on the southeast corner of the courthouse lawn starting shortly after dawn and continuing until early to mid-afternoon each day of the festival.

The juried festival also includes games, food and entertainment for all ages. In 2015, the festival drew an estimated 80,000 people to Mt. Vernon for the three day weekend!