CHAPTER XII. 



THE GEOLOGY OF WASECA COUNTY. 



BY WARREN CPHAM. 



Situation and area. Waseca county (plate 15, page 395) lies in the south 

 part of Minnesota, in the second tier of counties north of Iowa. Its largest 

 town and county seat is Waseca, in Woodville township, about 65 miles 

 distant, in a direction a little west of south, from Saint Paul and Minneapolis, 

 93 miles west of Winona, and 40 miles north of the Iowa line. This county 

 is a rectangle, twenty-four miles long from north to south and eighteen 

 miles wide from east to west, including twelve townships of the govern- 

 mental surveys, each of which, six miles square, is an organized civil town- 

 ship. The area of Waseca county is 437.01 square miles, or 279,685.91 

 acres, of which 11,524.16 acres are covered by water. v 



SURFACE FEATURES. 



Natural drainage. The Le Sueur river has its farthest sources in the 

 southeast part of Waseca county and in the adjoining edges of Steele 

 and Freeborn counties. This stream and its tributaries drain all of Wa- 

 seca county excepting its northeast corner. 



The main Le Sueur river runs from the southeast corner of this county northerly six miles 

 through the east part of New Richland; then westerly through southern Otisco, into the south- 

 east part of Wilton; then again northerly six miles to Carr's ford, in the southeast part of Saint 

 Mary township; and thence westerly eleven miles through the north part of Saint Mary and Al- 

 ton. On the right this stream receives small tributaries in sections 7 and 6, Otisco, the latter be- 

 ing named McDougal creek, and in sec. 34, Saint Mary. Its only considerable tributary on the 

 left in this county is Boot creek, which comes from the south, approximately coinciding in ita 

 course with the boundary line between New Richland and Byron. 



About a quarter of Waseca county, at the southwest, sends its surplus waters to the Le 

 Sueur by the Big Cobb river, which flows through the south part of Vivian; while a branch of it, 

 the Little Cobb river, and Bull run, tributary to the last and the outlet of Silver lake in Wilton, 

 flow westerly across Freedom township, into Blue Earth county. 



At the northwest, nearly all of Janesville, western losco, and the north part of Alton are 

 drained by the way of lake Elysian and its outlet, which also passes into Blue Earth county and 



