GLACIAL FEATURES OF ST. CROIX DALLES REGION 241 



easterly direction across the St. Croix, advanced some distance into 

 Wisconsin. 



Topography.— In this region the topography, with the exception 

 of postglacial erosion by the river and a few minor streams, is largely 





uriftless 

 Area. 



Fig. i.— Sketch map, showing the general relations of the area of the St. Croix 

 Dalles quadrangle. Data from maps of Wisconsin and Minnesota State Reports. 



the work of the ice of the red drift. In the western part the covering 

 of gray till, and the leveling action of the ice which made it, have 

 modified the original red surface somewhat, though not enough to 

 disguise it effectively; in the eastern portion it remains unaltered, 

 so far as later ice advances are concerned. The most prominent 

 features of this topography are three roughly parallel, or concentric 



