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.
Iroquoian languages
Attempts to link the Iroquoian, Siouan, and Caddoan languages in a Macro-Siouan family are suggestive but remain unproven (Mithun 1999:305).