312 THE GLACIAL LAKE AGASSIZ. 



FROM MILNOR NORTH TO SHELDON. 



(PLATE XXVII.) 



The highest level of Lake Agassiz near Miliini- is marked by the ]\Iilnor 

 beach, abeady mentioned, where it is crossed by the railroad. This beach 

 is fine clayey sand, in somewhat irregular and interrupted low ridges and 

 teiTaces, abutting at the west on undulating till, which gradually i-ises 10 

 or 20 feet higher, while on the east a descent of 10 or 15 feet within about 

 20 rods is succeeded by a flat area, which thence sinks very slowly north- 

 eastward. The elevation of the Milnor beach at the railroad is 1,086 feet, 

 and at Mr. G. V. Dawson's house, at the middle of the east side of section 

 22, township 133, range 54, 1,092 feet. Its course between these points is 

 north-northwest, and this is continued to the mouth of a former channel of 

 the Sheyenne River, near the center of section 4 in this townsliip, 3 miles 

 east from the most southern bend of the river. 



During all the stages of Lake Agassiz the Sheyenne River brought 

 into it much sediment, carrying the clay fiirther than the sand and gravel, 

 which were laid down near the river's mouth. Extensive areas of these 

 originally flat beds have been changed by wind action to irregular groups 

 and belts of sand hills or dunes, which vary from a few feet to more than 

 100 feet in height above the surrounding level. Besides the large tract of 

 these dunes before described east of the Sheyenne River, others of even 

 greater extent and equally conspicuous border the river and reach 2 or 3 

 miles from it in the northeast part of township 135, range 54, and along its 

 next 15 miles. 



Watercourses formerly occupied by this stream are found AACst of the 

 Milnor beach. One of them is marked by a sandy flat, which reaches 

 from the present course of the Sheyenne River, in section 1, township 133, 

 range 55, southeastward through township 133, range 54, to the vicinity 

 of Milnor. Another runs from near the middle of the southwest quarter of 

 section 32, township 134, range 54, about 1^ miles east-southeast to the 

 middle of section 4, township 133, range 54. This is a channel 30 to 50 

 rods wide, about 40 feet below a ridge of coarse gravel, which extends 

 along its northeast side, dividing it from the lower area that was covered 

 by Lake Agassiz and from the present valley of the river. The crest of the 



