Dhegihan languages

The Dhegihan languages are a group of Siouan languages. They include Kansa–Osage, Omaha–Ponca, and Quapaw. Their historical region included parts of the Ohio and Mississippi River Valleys, the Great Plains, and southeastern North America. The shared Dhegihan (Degihan) migration history and separation story places them as a united group in the late 1600s near the confluence of the Ohio and Tennessee rivers (southern Illinois and western Kentucky), which then moved westward towards the Missouri River and separated. 
Kansa and Osage can be understood by each other, as can Omaha and Ponca. 
The 2nd Annual Dhegiha Gathering in 2012 brought Kansa, Quapaw, Osage, Ponca and Omaha speakers together to share best practices in language revitalization.