470 J. E. TODL> THE CHANNEL OF THE MISSOURI ^TTER 



Page 



Head erosion promiaent ^&- 



Tlie Bis Berthold bend ^92 



IXTEODUCTOET 



For Years it has been belieTed that the Missouri River owed its present 

 course verr largely to the influence of ice-sheets. This was first recog- 

 nized by General G. K. Warren in ISGS. Li Ic'lo Pro:. A. G. Leonard. 

 State Geologist of Xorth Dakota, published his conclusion, after some 

 years of study, that the channel of the Missouri through Xorth Dakota 

 was of Teritiary origin, and that the ic-e-sheets of the Pleistocene had 

 little effect upon its course. 



This conclusion is diametrically opposed to that of South Dakota geolo- 

 gists ; consequently the writer undertakes in this paper to show the errors 

 of Dr. Leonard and, on the contrary, the reasons for believing that before 

 the ice-sheet influenced the ^Missouri Eiver the Missouri was made up 

 of various streams leading to the north and east, and that the ice, by 

 damming them, caused the wat-er accumulating along its western edge to 

 form a series of lakes and channels which eventually determined the 

 present course of the Missouri of the Pleistocene in the Wisconsin stage. 



AcKXOWIJEDGirENTS 



The material for this paper has mostly been gathered incidentally 

 during several seasons' work, years ago, for the United States Geological 

 Survey and for the South Dakota etiological Survey. More recently 

 the Chicago, ^lilwaukee and Saint Paul Railway Company presented me 

 with profiles of their lines west of the Missouri Eiver in South Dakota, 

 and the Minnesota and Saint Louis Eailroad Company did likewise with 

 their lines to Leola and Le Beau. 



I am most grateful to Messrs. Xorbeck and Xicholson, well-drillers, 

 Eedfield, South Dakota, for the free use of an auto and chauffeur for a 

 week in Cheyenne Eiver Lidian Eeservation. 



The writer has not been personally familiar with facts concerning the 

 Missouri above Bismarck and has depended almost entirely upon the 

 reports of the Xorth Dakota Geological Survey and a few articles in 

 geological periodicals. 



De. Leoxaed foe THE Affiemative 



Dr. Leonard, in his paper before the Geological Society of America, 

 gives his reasons so clearly and concisely we quote them in full. We 



