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.
Montmartre, Saskatchewan
Assiniboine is a Siouan language. It was derived from other Sioux dialects at the same time as other Sioux languages were being diverged and differentiated from each other. The language today is endangered, and there are very few speakers that are living. Most Assiniboine today are English speakers.