Tebruaey 20, 1914] 



SCIENCE 



267 



rises gradually to the lowest point of the 

 divide below the Missouri and James near 

 Hillsview, at an altitude of 1,850 A. T. 

 Thence is a gradual descent to the valley of 

 the James near Aberdeen. That the axis of 

 a lobe of ice lay along this line during the 

 Wisconsin stage is shown by hills lying to 

 the north and south, and these with the be- 

 iore mentioned ridge lying along the east 

 side of the Missouri are all covered with 

 morainic drift. It is not difficult to con- 

 ceive that the preglacial Grand and Mo- 

 reau, flowing 200 to 250 feet higher than 

 now, went east to the James. 



4. Cheyenne and Bad Rivers. — These con- 

 stitute another pair which, probably uniting 

 near Pierre, passed east to the James River 

 Valley. The Cheyenne at that time lay 

 further south in its lower course, as is indi- 

 cated by broad high terraces. It passed 

 south of Sully Buttes and eastward 

 through the northern part of Hyde and 

 Hand counties and the valley of Turtle 

 Creek to the James near Redfield. Bad 

 River may have joined it near the mouth of 

 Okobojo Creek or may have followed the 

 present course of the Missouri to the mouth 

 of Medicine Knoll Creek and up its course 

 to a junction in eastern Sully county. 

 There is similar and clearer evidence of 

 a former ice lobe here than that found in 

 the last case, viz., the moraines to the north 

 and south and along the east bluffs of the 

 Missouri. The valley is so well marked that 

 it is popularly known as the Ree Valley. 

 The hills north and south rise to 2,000 A. T. 

 The lowest part of the divide in the valley 

 is 1,650 to 1,675 A. T. The depth of the 

 glacial drift may reach 200 to 250 feet. 



5. White River. — The course of this river 

 is about as easily traceable east of the Mis- 

 souri as that of Heart River, and for a sim- 

 ilar reason, viz., because the ice did not 

 quite reach to the Missouri in its valley. 

 There are several prominent terraces along 



White River, one 200 to 250 feet above the 

 stream. At about the same level is a valley 

 about two miles wide which runs from the 

 mouth of that river northeast nearly 25 

 miles, where it is crossed by a moraine a 

 little west of White Lake. White Lake 

 may be considered in it and the depression 

 continues down the Firesteel to the James, 

 and then northward to join the Cheyenne. 

 Red Lake occupies a portion of this same 

 valley. Several miles south of White River 

 is the old divide between it and Niobrara 

 River. It stands out prominently as a high 

 range of flat-topped buttes capped with 

 Tertiary sandstone. The gorge of the Mis- 

 souri through it is 750 feet deep. The 

 preceding rivers after reaching the James 

 Valley, which was then imperfectly de- 

 veloped, converged to a point northeast of 

 Aberdeen, where there is a prominent gap^ 

 in the highland east of the James, a little 

 north of the south line of North Dakota. 

 It is the wide valley of an intermittent 

 stream called the Wild Rice River. That 

 stream heads close to the James River and 

 the divide between is not over 30 feet higher 

 than the latter. The Wild Rice descends 300 

 feet in 60 miles and joins the Red River of 

 the North. 



We may conclude, therefore, that White 

 River turned northward, joined the Chey- 

 enne near Redfield and Grand River north 

 of Aberdeen and met the Cannon Ball and 

 Heart rivers coming from the north and all 

 formed an important stream which found 

 its way eventually to Hudson Bay, as Red 

 River does to-day. It is possible that the 

 two from the north may have found courses 

 along the Cheyenne and not joined those 

 from the south till later. No trace of the 

 old courses could be found now, for the ero- 

 sion of the Pleistocene must have lowered 

 the surface scores of feet below the bottoms 

 of the old valleys. 



6. Niobrara River. — The valley of this 



