The Siouan speakers are a Native American language family that includes four distinct tribes: the Otos, Osages, Otoes, and Iowas. The Otos are a tribe of Native Americans who historically lived in the Great Plains region of the United States. The Osages are a Native American tribe who traditionally lived in the present-day states of Arkansas, Missouri, Kansas, and Oklahoma. The Otoes are a Native American tribe who historically lived in the Great Plains region of the United States. The Iowas are a Native American tribe who traditionally lived in the present-day states of Iowa, Minnesota, Nebraska, and South Dakota.