FACTORS 45 
/ sHEET ibe aie 
Tue HISTORY OF THE CHICAGO REGION 
Fic. 1.—Showing the region of the Great Lakes when the Wisconsin ice sheet 
was retreating from its maximum extent (after Atwood and Goldthwait). 
Fic. 2.—A part of the same area, showing the drainage of the ice sheet by the 
Kankakee and Huron rivers through Dowagiac Lake (from Lane after Leverett). 
Fic. 3.—Showing a later stage of the retreat of the ice sheet—the Glenwood 
stage (from Lane after Leverett). 
Fic. 4.—A later stage of the same—the Calumet stage of Lake Chicago (from 
Goldthwait after Leverett and Taylor). 
Fic. 5.—A still later stage—probably the Tolleston stage (from Lane after 
Leverett). 
A post-Tolleston stage (from Goldthwait and Atwood after Leverett 
and Taylor). 
