372 COUNTY AND REGIONAL GEOLOGY. 



Drainage and Surface Characters. It is drained prin- 

 cipally by the npper branches of the West Nodaway and the 

 East Nishnabotany. These npper branches are designated 

 as creeks in this county, as such small streams shonld always 

 be, and have separate names applied to them. Thus, the 

 main branch of the Nodaway, which drains the southeastern 

 part, is called Sixteen Mile creek, while in the northeastern 

 part the East Nishnabotany becomes divided up into Indian, 

 Buck, Troublesome, Turkey, and other creeks and loses its 

 identity in them. These creeks drain the county completely, 

 and give considerable diversity to its surface. The whole of 

 the county lies within the area drained by the tributaries of 

 the Missouri river, but its extreme northeastern corner reaches 

 almost to the Great Watershed. It is estimated from the 

 neighboring levels along the line of the Chicago, Rock Island, 

 and Pacific Railroad, that this corner of the county is about 

 nine hundred and twenty feet above low water in the Missis- 

 sippi river at Davenport, or one thousand four hundred and 

 forty-eight feet above the level of the sea. 



Much the greater part of the surface is prairie, and between 

 the valleys of the larger streams it is, as usual, gently undu- 

 lating. The character of the valleys of its creeks is almost 

 entirely that of the drift valleys, the sides being gently 

 sloping, and nowhere steep. A few exposures of rock in the 

 valley of the Nishnabotany, produce some steepness of its 

 sides at a few points, but these are rare exceptions. The 

 Bluff Deposit thins out upon the surface of the uplands in 

 the western part of the county, so that the greater part of the 

 soil is the fine drift soil of the prairies. The general aspect 

 of the eastern half of the county is that usually presented by 

 the gently undulating prairies of southwestern Iowa, but the 

 western half, in the vicinity of the streams, is rather more 

 diversified. The valley of the Nishnabotany still retains its 

 characteristic beauty in this county, until it becomes subdi- 

 vided into the numerous creeks before mentioned. The 

 valleys of these creeks produce a pleasing diversity of surface 

 in that part of the county drained by them. > 



