The following Siouan Languages tree is based on the information in the Ethnologue.
Siouan Languages
Catawba Stock
Catawba (USA)
Siouan Proper Stock
Central Family
Mandan Branch
Mandan (USA)
Mississippi Valley Branch
Chiwere Group
Iowa-Otoe (USA)
Dakota Group
Assiniboine (Canada)
Lahkota (USA)
Stoney (Canada)
Dhegiha Group