Siouan languages
Siouan or Siouan–Catawban is a language family of North America that is located primarily in the Great Plains, Ohio and Mississippi valleys and southeastern North America with a few other languages in the east.
Assiniboine language
Sioux, Assiniboine, and Stoney are closely related languages of the Dakota family. Many linguists consider Assiniboine and Stoney to be dialects. However, they are mutually unintelligible. Parks and DeMallie report that they are not variant forms of a single dialect, but that Assiniboine is closer to the Sioux dialects than it is to Stoney. The exact number of interrelationships among the subdialects and dialects comprising this continuum is unknown.