PIPESTONE AND ROCK COUKTIES. 535 



Topography.) 



above the ocean. Where Rock river leaves Pipestone county its water 

 surface is fifteen hundred feet above the ocean, and where it leaves the 

 state it is about 1,350 feet. This valley is about fifty feet below the gen- 

 eral level in Burke township, but its bluffs increase in hight toward the 

 south, reaching seventy-five and eighty feet in Osborne, the surrounding 

 country being about twenty-five feet still higher. Chanarambie creek is 

 likewise deeply channeled in the drift. There are here also a great many 

 sharp ravines, like the ravines in the Bad Lands of Montana, that suggest 

 the existence of some of the friable strata of the Cretaceous. The Rock river 

 valley, farther south, is cut from seventy-five to one hundred feet below 

 the general level of the country, and in Rock county receives a number of 

 small tributaries from the east, each of which flows in a deeply cut valley 

 from fifty to a hundred feet below the general level. This valley, which 

 is furnished with a fertile bottomland from a half mile to one mile wide, 

 is enclosed by bluifs in the southern part of Rock county that do not have 

 the usual steepness, as if recently undermined by the current of the river, 

 but which rise by moderate slopes to the general level of the undulating 

 upland. The same feature is observable in the bluffs of Beaver creek, 

 which, like the Kanaranzi, Champepadan, Elk and Split Rock creeks, have 

 cut their valleys from forty to sixty feet below the general surface. Rock 

 county in general has a surface that is broadly undulating, the swells 

 sometimes showing a trending to a north-south direction. 



These are emphatically and characteristically prairie counties, and 

 are nearly level in some portions. They are more undulating in their 

 eastern portions. The west-facing bluffs are usually more precipitous than 

 the east-facing. They are also more stony with foreign boulders, a cir- 

 cumstance, however, that may be owing to the action of the prevailing 

 western winds, combined with the drying effect of the southwestern sun in 

 summer, which would uncover and keep bare the coarser materials of the 

 surface by blowing away the sand and clay during the dry windy months 

 of the year, while the bluffs on the west side would not only not receive 

 such winds, but would serve to collect all particles flying toward the east 

 from the prairie above. 



The range of high land running northwestward from Mound in Rock 

 county, is a conspicuous object in the horizon from the north and east. 



