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.
Siouan languages
Collaborative work involving a number of Siouanists started at the 1984 Comparative Siouan Workshop at the University of Colorado with the goal of creating a comparative Siouan dictionary that would include Proto-Siouan reconstructions. This work yielded a different analysis of the phonemic system of Proto-Siouan, which appears below: