26 



TWELFTH REPORT. 



the St. Louis River to Kettle River and thence to the St. Croix and this 

 drew the water down below the level of the outlet of Lake Upham. To 

 distingTiish tliis lower lake stage in the St. Louis drainage basin it has 

 l)een named by Winehell Lake St. Louis. A little further shrinking of 

 the ice border exposed the headwaters of Xemadji River, a stream that 

 conies into the head of Lake Sujierior from the west-southwest, and 

 there Avas formed a small lake about 500 feet above Lake Superior level, 

 known as Lake Xemadji. It received the melting waters from the end 

 of the Superior lobe and discharged a large volume of water down the 

 Kettle River vallej- into the St. Croix, though only 30 square miles in 



8» 



Si- 



Fig. 1. Superior Ice Lobe and Lake LTpham. 



area. During the life of each of these lakes the ice sheet still com- 

 pdetely covered the area of Lake Superior. 



As the ice border shrank vrithiu the limits of the western end of 

 Lake Superior a large body of water, named Lake Dulutli (Fig. 2), 

 came into existence. Its outlet was southward from the head of Brule 

 River in northwestern Wisconsin into the St. Croix River. While 

 this was ?til! a small lake there was formed another lake farther east 

 called Lake Ontonagon for it covered much of the Ontonagon drainage 

 basin in the western part of the northern peninsula of Michigan. It 

 discharged westward along- or near the ice border into Wisconsin where 

 it joined Lake Duluth in the discharge through the St. Croix valley. 

 Its outlet made a descent between 150 and 200 feet, however, before 

 reaching Lake Duluth, With the recession of the ice border Lake On- 



