Western Siouan languages
The Western Siouan languages, also called Siouan proper or simply Siouan, are a large language family native to North America. They are closely related to the Catawban languages, sometimes called Eastern Siouan, and together with them constitute the Siouan (Siouan–Catawban) language family.
Languages of the United States
Dakota is a Siouan language with 18,000 speakers in the US alone (22,000 including speakers in Canada), not counting 6,000 speakers of the closely related Lakota. Most speakers live in the states of North Dakota and South Dakota. Other Siouan languages include the closely related Winnebago, and the more distant Crow, among others.