LIST OF THE LAKES 1 1 1 



Outlet iibovo 

 Niime. t'lt' sea. 



Feet. 



21. Lake Uphain 1300 



22. Lake Norwood 1450 



23. Lake Duiika 1495 



24. Lake Elftnian 1700 



25. Lake Onnainani 1370 



26. Lake Oiuimi 1360 



It should be further premised that uiost of these hikes have not been 

 traced out by a continuous following of their beach lines, and some o^ 

 them probably can not be so defined, owing to their shifting level or 

 their short duration. Their outlets being determined, the same contour 

 lines have been assumed to show sufficiently for this purpose the area 

 and shape of the several lakes. 



GkiNeral Manner of Retreat of the Ice-border 



It has been said repeatedly in the reports of the Minnesota surve}'' 

 that the ice came on Minnesota from two directions, from the northeast 

 and from the north-northwest. This is true at least of the glacier bodies 

 that invaded the state. The originatiqn of the neve which subsequentl}'' 

 went to form the glaciers was probably earliest on the high plateaus — 

 that is, on central Minnesota and northwestern Wisconsin. Distinct 

 glaciers formed first and continued longest in the lowlands, and disap- 

 peared first from the highlands. In other words, the two great ice-lobes, 

 which deployed first independently and at length confluently and lastly 

 retreated separately, had their central axes along the main depressions. 

 One came southward, up the valley of the Red river of the North, turned 

 southeastward!}^ down the Minnesota River valley, entered the Des 

 Moines valley, and extended into Iowa. The other originated as a mov- 

 ing, flowing ice mass essentially in the valle}^ of the western end of lake 

 Superior, and in the upper part of the Mississippi valley it became con- 

 fluent with its western cotemporary, and thence southward they alter- 

 natingly advanced on and retreated from each other along a line of 

 contact whose complex and copious morainic accumulations have added 

 great diversity to the drift features of several counties, the difficulties of 

 which have not yet been full}" surmounted. These two ice-lobes retreated 

 as they came, one north-northwestwardly and the other east- northeast- 

 wardly, and the record which now remains is essentially that produced 

 by this retreat. There was an earlier ice-sheet which extended farther 

 south and which was followed by a period of land surface and vegeta- 

 tion. There is no doubt that that earlier drift surface had some effect 



