CHAPTER IX. 



THE GEOLOGY OF DODGE COUNTY. 



BY M. W. HARRINGTON. 



(UK/ (u-i'ii. This county occupies the angle formed by the 

 boundaries of the two la:;t described, being west of Olmsted and north of 

 Mower. Its form is that of a rectangle, being four towns long north and 

 south, and three in width east and west. Its total area is 43>S.6"> square 

 miles, or '2S().7:!s. ( .)U acres, of which 279.956.47 are land, and 782.43 are water, 

 according to the measurements of the original survey by the United States 

 surveyors, on record in the office of the State Auditor at St. Paul. 



SURFACE FEATURES. 



Natttni/ ilniiiiiif/t'. The surface waters leave the county for the most 

 part toward the east and northeast by means of the branches of the Zum- 

 hro river. The largest of these is the south branch of the middle fork 

 of the Zumbro, which rises in Rice lake, on the western border of the 

 county, and flows eastward through nearly the central portion of the 

 county. The north branch of the same stream has its source in the wet 

 prairies in the northwest corner of the county, and flows nearly eastward 

 also. The south branch of the Zumbro reaches this county by two small 

 streams which have their sources in the southeastern part. The upper 

 tributaries of the Cedar river, known as the west, middle and east forks, 

 rise in Westfielcl and Hayh'eld townships, in the southwestern corner of the 

 county. These sources of the Cedar consist of a series of shallow lagoons 

 which during the summer and autumn are not connected visibly by water 

 currents. Lying in the broad depressions of the high prairies, they act as 



