NE-SAW-JE-WON 



present level of Lake Erie. At this stage the over-flow waters 

 escaped over a "col" (low place between hills) in the im- 

 pounding moraine and flowed from the lake-basin south- 

 westward, past the site of Fort Wayne, to the Wabash River 

 which had been one of the escape channels for the melt-water 

 before the lake was formed. Thus the first outlet of the Great 

 Lakes was via the Wabash and Ohio rivers to the Mississippi 

 and the Gulf of Mexico. The Maumee River now flows into 

 Lake Erie over the bed of this ancient lake, hence its name — 

 Lake Maumee. (Figure 4.) 



Early Lake Chicago; Lake Jean Nicolet 



Shortly after the formation of the first Lake Maumee, 

 another long narrow lake began forming at the foot of the 

 ice lobe in the Lake Michigan basin, between the retreating 

 ice and the morainic barrier. This was the beginning of 

 glacial Lake Chicago, the ancestor of Lake Michigan. Its out- 

 let was through the lower channel of the present Des Plaines 

 River, into the Illinois, and thence to the Mississippi and the 

 Gulf of Mexico. Probably only a little later two small lakes 

 formed at the southern end of the ice lobe in the Green Bay 

 basin. The outlet of one of these was southward to Rock 

 River and of the other southwestward to Wisconsin 

 River, thence to the Mississippi and the Gulf. These lakes 

 later united, forming glacial Lake Jean Nicolet which is of 

 interest but of relative unimportance. It did not last long 

 enough to make strong shores as an independent lake, for it 

 soon merged with Lake Chicago, when the retreating ice 

 opened passage to that lake. 



Very much later a similar crescent-shaped lake was formed 

 around the western end of the Superior ice lobe. It was known 

 as glacial Lake Duluth, the ancestor of Lake Superior, and 

 discharged southward through St. Croix River to the 

 Mississippi. 



From these four small crescent-shaped glacial lakes, ini- 



34 



