Tarkio is a city in Tarkio Township, Atchison County, Missouri, United States. The population was 1,583 at the 2010 census . It was platted in 1880 and incorporated in 1881. The name "Tarkio" is from a Native American word meaning "place where walnuts grow". Historically, the economy of the city was based on agriculture and its status as a college town.