BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 12, pp. 13-24 November 30, 1900 



PLEISTOCENE ICE AND RIVER EROSION IN THE SAINT 

 CROIX VALLEY OF MINNESOTA AND WISCONSIN 



BY WARREN UPHAM 



(Read before, the Society June 26, 1900) 

 CONTENTS 



Page 



Introduction 13 



The Saint Croix river and basin 14 



Table of altitudes 15 



Preglacial rivers in the Saint Croix valley 16 



Pleistocene erosion of the Dalles 18 



Outlet of the Western Superior glacial lake 21 



Origin of lake Saint Croix and lake Pepin , 22 



Summary of the geologic history of the Saint Croix Dalles 23 



Introduction 



The theme of this paper was first considered somewhat fully by the 

 present writer in a lecture, March 18, 1896, entitled " The Saint Croix 

 river before, during, and after the Ice age." This lecture was given at 

 Taylors Falls, Minnesota, as one in a series designed to direct public 

 attention to the Interstate park, recently set apart by legislative enact- 

 ments of Minnesota and Wisconsin, on each side of the Saint Croix 

 river at its Upper Dalles, closely adjoining the towns of Taylors Falls, 

 Minnesota, and Saint Croix Falls, Wisconsin. The series of lectures was 

 published in 1896 by Honorable George H. Hazzard, the Interstate Park 

 Commissioner of Minnesota; but my lecture was withheld from publi- 

 cation in geologic literature, excepting very brief notes,^ on account of 

 my hope for further opportunities of field observation and study of this 

 subject. 



My chief conclusion, that in the Glacial period the Saint Croix river 

 first began to occupy the part of its valley including the rock gorges of 

 the Upper and Lower Dalles, was soon accepted by Doctor Charles P. 



*Am. Geologist, vol. 17, p. 260, April, 1896, and vol. 18, p. 223, Oct., 1896. 

 Ill— Bum,. Geoi,. Soc. Am., Vol, 12, 1900 (13) 



