Febbuaey 20, 1914] 



SCIENCE 



265 



drainage was largely to the northeast and 

 the ice changed it to the southeast. 



The exceptional or anomalous course of 

 the present Missouri is shown by the fol- 

 lowing facts. The Missouri at Ft. Steven- 

 son, where it turns sharply to the southeast, 

 is 1,720 feet A. T., while the Souris Eiver, 

 forty miles northeast, is 200 feet lower and 

 from there is an open course to Hudson 

 Bay, 900 miles away in a straight line. In- 

 stead of finding its way thither it reaches 

 the Gulf of Mexico at just about twice that 

 distance. To be sure other rivers show sim- 

 ilar eccentricities, but they have mountain 

 ranges to explain their action. Here there 

 is nothing of that sort, but, on the contrary, 

 only soft rocks lying horizontally. More- 

 over, the tendency for the Missouri to run 

 at right angles to the direction of slope is 

 shown further by the following facts: at 

 Bismarck it is 220 feet higher than the 

 James River at Jamestown, 105 miles east, 

 and 400 feet above the Chyenne, 10 miles 

 further east; at Pierre it is about 200 feet 

 above the James, 105 miles east, and at 

 Chamberlain 100 feet higher than the 

 James near Mitchell, 66 miles east. At 

 Sioux City the Missouri is 130 feet higher 

 than the Des Moines at Ft. Dodge, 110 

 miles away, and at Council Bluffs 200 feet 

 higher than the Des Moines, 115 miles east. 

 At Kansas City it is about 300 feet higher 

 than the Mississippi at Hannibal, about 200 

 miles east. This illustrates strikingly the 

 tendency of the Missouri to follow the 

 strike of the surface rather than the dip. 



This anomaly is commonly ascribed to 

 the influence of Pleistocene ice sheets. In 

 general it is safe to suspect that the pre- 

 glacial drainage of the region was toward 

 the east or northeast. This agrees with the 

 fact that streams along the line of the pres- 

 ent Missouri trend eastward, except in the 

 vicinity of glacial deposits, viz., from the 



vicinity of Williston, N. D., to Kansas City, 

 Missouri. 



A. THE PROBABLE PRE-PLEISTOCENE DRAINAGE 



ALONG THE LINE OF THE PRESENT 



MISSOURI RIVER 



The conclusions offered here should be 

 valued carefully according to their weight. 

 Some may be considered fairly established ; 

 others are given only provisionally. More- 

 over time permits us to indicate them only 

 briefly without stating them so fully as 

 might be desired. The main tributaries of 

 the Missouri are from the west and have 

 uniformly a persistently eastward direction. 

 Furthermore, they may be grouped into 

 clusters of two or three which converge as 

 they approach the Missouri, and in several 

 cases corresponding valleys are discover- 

 able east of the Missouri. We will consider 

 these groups in order. 



1. The Missouri and Little Missouri 

 Rivers. — The upper Missouri keeps a quite 

 persistent easterly course from the moun- 

 tains till it approaches the glacial drift near 

 Nesson, N. D. The Yellowstone flowing 

 northward joins it 40 miles west at Buford. 

 The Little Missouri, with a course parallel 

 to the latter, formerly joined the Missouri 

 at Nesson, but now it leaves its old channel 

 about 50 miles south of its old mouth, turns 

 east and joins the present Missouri near 

 Ft. Berthold. In view of these facts, prob- 

 ably the flrst suggestion which comes to 

 mind is, that before the Pleistocene the 

 Little Missouri joined the Missouri at Nes- 

 son and both continued their way eastward 

 to the bend of Souris River and thereby 

 reached Hudson Bay. This seems to agree 

 with the fact that a terrace and old chan- 

 nel more than 100 feet higher than the pres- 

 ent river leads eastward over a dozen miles 

 into the morainie drift, but such a conclu- 

 sion is forbidden by the discovery of a chan- 

 nel corresponding in height and size several 



