<P> The Great Sioux Nation was the political structure of the Sioux in North America at the time of their contact with Europeans and Euro - Americans . Most of the peoples speaking a Siouan language were members of the Očhéthi Šakówiŋ (pronounced (oˈtʃhethi ʃaˈkowĩ)) or Seven Fires Council . The seven members are sometimes grouped into three regional / dialect groups (Lakota, Western Dakota, and Eastern Dakota), but these mid-level identities were not politically institutionalized . The seven smaller groups were separate members of one confederacy . </P> <P> The Great Sioux Nation is divided into three linguistically and regionally based groups and several subgroups . Linguistically, all three language groups belong to Siouan languages . </P>

What are the three tribes that make up the sioux nation