BIG STOKE AND LAC QUI PARLE COUNTIES. 



Topography.] 



in prolonged, smooth slopes to bights 10 to 20 or 30 feet above the similarly 

 irregular depressions. In these hollows lie the lakes and sloughs of this 

 region, from 5 to 25 feet below the average hight of their vicinity. The 

 lake shores are often gentle slopes, but in many places have been eroded by 

 the action of waves, until they form a steep bank 5 to 15 feet high, bordered 

 at its foot by boulders and coarse shingle that have been left while the finer 

 portions of the till have been washed away and strown upon the lake-bed 

 and along other parts of the shore. 



The absence of lakes in most of Lac qui Parle county, as also of Yellow 

 Medicine county on the south, seems quite remarkable in contrast with 

 their frequent occurrence in Big Stone and other adjoining counties, and 

 indicates that different conditions attended the deposition of the till upon 

 these districts. A shallow glacial lake (page 461) seems to have bordered 

 the ice-sheet in its recession across Lac qui Parle county, somewhat level- 

 ing and evening up the surface of the drift, thus filling many hollows 

 which would otherwise be occupied by lakes. 



The most interesting feature in the topography of this region is the 

 deep channel or valley that was excavated by the river Warren, the outlet 

 of lake Agassiz, and is now occupied by lakes Traverse and Big Stone and 

 the Minnesota river. Its description, and its origin and history, and notice 

 of the series of drift hills and knolls forming the third terminal moraine, 

 which crosses western Lac qui Parle county, are presented farther on, in 

 treating of the glacial drift. 



Channels have also been eroded in the drift-sheet by the tributaries of this main valley. 

 These increase in depth and width from their sources to their mouths. Indenting their bluffs, 

 as well as those of the great valley, are frequent ravines, cut by rivulets, some of which are fed by 

 perennial springs, while others are dry through most of the year. The branches of the Yellow 

 Bank and Lac qui Parle rivers have excavated channels 25 to 50 feet below the general level; and 

 from their junctions to the Minnesota valley, these rivers are bordered by bluffs 50 to 75 feet 

 high. 



Elevations, Hastings & Dakota division, Chicago, Milwaukee & St. Paul railway. 

 From profiles in the office of George H. White, engineer, Minneapolis. 



M iles from Feet above 

 Hustings. the sea. 



At the east line of Big Stone county 184.1 987 



Correll 186.9 980 



Odessa 194.3 963 



Stony run, track 195.1 965 



Stony run, water 195.1 958 



Summit, grade 199.0 1002 



Ortonville 200.9 990 



Big Stone lake 202.0 962.5 



