Stoux City dcademy of Science and Letters. 137 
GENERAL PHYSIOGRAPHIC RELATIONS. 
The Great Plains Province in which Dakota County 
lies extends from north to south through the middle 
United States. It merges insensibly on the west into the 
higher, broad Plateau Province which lies between it and 
the Rocky mountains, and blends in like manner to the 
east into the lower Prairie Region of the Mississippi 
Valley. 
TOPOGRAPHY. 
General description—To the casual observer the sur- 
face of northeastern Nebraska and northwestern Iowa 
does not at first suggest a plain. Missouri River is seen 
flowing in a monotonously flat valley, 8 to 20 miles wide, 
bordered by irregular bluffs that rise 150 to 300 feet. At 
intervals of a few miles smaller streams emerge from 
either side on this flat through shallow valleys and dis- 
appear in swamps or wind sluggishly across to the 
greater stream. Between the valleys of the smaller 
streams many steep, narrow ravines cut the faces of the 
bluffs, and in several places isolated hills or peaks stand 
out abruptly as though detached from the bluffs, while 
at others, narrow points or spits extend out into the flat 
from the higher land in the background. 
From a view point on one of the higher bluffs on 
either the Nebraska or the Iowa side the scene presents 
a different aspect. Here also the casual observer does 
not readily see the resemblance to a plain in the treeless 
surface so intricately carved into sharp, winding ridges, 
crooked, V-shaped valleys, and graceful peaks grouped 
in wild confusion as far as the eye can see on either side 
of the flat, trough-like depression through which the 
river meanders. 
The marked uniformity, however, in the heights to 
which the ridges and peaks rise suggests to the imagina- 
tion that to fill all the intervening depressions including 
the great flat river valley to the level of the higher points 
would produce a great high plain. This would in truth 
be a restoration of a former physical condition of the 
surface. 
That the dissection of this plain is due to erosive 
forces is particularly well illustrated during every rain 
storm or at times of melting snows. At such times the 
