Siouan languages
Authors who call the entire family "Siouan" distinguish the two branches as "Western Siouan" and "Eastern Siouan" or as "Siouan-proper" and "Catawban". Others restrict the name "Siouan" to the western branch and use the name "Siouan–Catawban" for the entire family. Generally, however, the name "Siouan" is used without distinction.
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.