The Michigamea (or Mitchigamea), when "found" by European explorers in the late-1600's, were located in northeast Arkansas and southeast Missouri on the west side of the
Mississippi River--the southern-most of the six main tribes of the
The Illiniwek Confederation. Other tribes in the alliance included
The Kaskaskia,
The Peoria,
The Cahokia,
The Tamaroa and
The Moingwena.
It is widely thought that this tribe fled Illinois, and the land and lake (Lake Michigan) that bears its name, due to constant conflict with the warring tribes of the Fox and Sioux from the north (Wisconsin).
About the end of the l7th century they were driven out of the Arkansas area by the Chickasaw (who claimed a good portion of land south of the Ohio River), crossing back over into Illinois and joining the Kaskaskia as a skelton of its former self.