PLATE IX. 



WINONA COUNTY, 1884. N. H. WINCHELL. 



With respect to the Mississippi river and the tributary drainage and consequent 

 channelling of the original rock surface, this county presents the same features as 

 Houston county, but in the northern and western portions these features are slightly 

 modified by a-scant deposit of northern drift, which fades out imperceptibly under 

 the loam. Besfdes this fringe of the glacial deposit along the west there is a notable 

 amount of northern drift in the Mississippi valley. This appears in the protected 

 angles of the bluffs, and is apparently closely connected in date and origin with a 

 gravelly terrace which also is conspicuous in numerous places in the tributary valleys. 

 It seems probable that a long tongue of the glacier descended the Mississippi gorge 

 as in a fjord, obstructing all the tributary streams, leaving a scant morainic deposit 

 along the bluffs, remains of which can be seen at Winona. Such spur from the 

 northern ice would also cause the terracing of the lateral streams. This terrace is 

 seen in many of the larger valleys, constituting the principal feature of their topog- 

 raphy. The upper portion of this terrace is frequently a loam undistinguishable 

 from the loam of the upland, but the lower portion consists of coarser sand, and 

 often of gravel. This terrace is about fifty feet above the flood plain adjacent. 



The general surface is covered everywhere by a clayey loam, which gives the 

 county its fine soil and agricultural capabilities. This loam becomes sandy at points 

 where a copious. supply of sand could be obtained from the St. Peter, Jordan or St. 

 Croix sandstones. 



The highest part of the county is south of St. Charles, where the Trenton hills 

 rise to 1,325 feet above the sea, the depot at St. Charles being 1,131 feet and situated 

 about at the top of the Shakopee limestone. The uplands along the Mississippi are 

 about 1,200 feet above the sea, but the crest of the limestone outcrop is about 1,100 

 feet. The Mississippi descends, between the north county boundary and the southern, 

 from 650 feet to 627 feet above the sea. 



The county has many copious springs of clear cold water, and as the streams 

 are largely maintained by these the brook trout is found in some of them. 



Important quarries are at Winona, in the Lower Magnesian limestone; also at 

 Stockton. Excellent brick are made at several places, especially at Dresbach. 



N. H. w. 



