Siouan languages
Siouan languages can be grouped into the Western Siouan languages and Catawban languages. The Western Siouan languages can be divided into Missouri River languages (such as Crow and Hidatsa), Mandan, Mississippi River languages (such as Dakotan, Chiwere-Winnebago, and Dhegihan languages), and Ohio Valley Siouan branches. The Catawban languages consist only of Catawban and Woccon.
Mandan
The Mandan language or "Nų́ų́ʔetaa íroo" belongs to the Siouan language family. It was initially thought to be closely related to the languages of the Hidatsa and the Crow. However, since the Mandan language has been in contact with Hidatsa and Crow for many years, the exact relationship between Mandan and other Siouan languages (including Hidatsa and Crow) has been obscured. For this reason, linguists classify Mandan most often as a separate branch of the Siouan family.