DRAINAGE. 43 



and 24, T. 63 N., R. 10 W.; in sees. 19 and 20, T. 63 N., R. 9 W.; in see. 1, 

 T. 64 N., R. 9 W., on Basswood Lake; at the falls between White Iron and 

 Birch lakes; and at the falls between White Iron and Stuntz lakes, just 

 below the south edge of the district. Of these the most accessible and the 

 best, and hence the ones most likely to be used, are the falls of the 

 Kawashachong, with a fall of about 32 feet, and Pipestone Falls, and the 

 falls between White Iron and Birch lakes. By a small dam at the outlet 

 of many of the lakes, large reservoirs could be formed and considerable 

 water power developed at little cost. 



Origin of the lakes. — General statements are very frequently made con- 

 cerning the lake regions of the Northern States lying within the limits of 

 the glacial drift, especially of the lake regions of Wisconsin and Minnesota, 

 which would lead the casual reader to suppose that all of the lakes in these 

 regions owe their origin solely to the agency of the di'ift, i. e., that they are 

 mere depressions within the general drift mantle which have been filled with 

 water. This is certainly true for a great number of the lakes in the drift- 

 covered portion of North America. In the case of the Vermilion district of 

 Minnesota, however, this simple mode of origin can be predicated of but 

 few of the lakes, and those are all small. The greater number of the lakes 

 have had a mixed mode of origin ; they owe their existence to pre-Glacial 

 erosion, which scooped out deep valleys, and then to the drift, which left 

 dams across these valleys at intervals. It is very probable that glacial 

 erosion was also active in widening and deepening these pre-Glacial 

 valleys, changing V-shaped into U-shaped valleys. Many of the lakes 

 empty over rocky rims. They occupy basins formed by the damming of 

 pre-Glacial valleys by drift, and their present outlets are higher than the 

 original mouth of the valley. However, the writer nowhere observed 

 rock-basin lakes which he could interpret as due to glacial erosion. 



The lakes in the western part of the district can be readily divided into 

 those which owe their present location and existence solely to glacial action, 

 and those which owe their existence to Pleistocene glaciation, but whose 

 present location and configuration are chiefly due to the geologic structure 

 of the pre-Glacial rocks and to pre-Glacial drainage. To the first kind 

 belong, among others, the oval or irregular lakes lying in the deep 

 morainal drift which stretches northeast-southwest through T. 61 N., R. 14 

 W., and T. 62 N., R. 13 W. 



