FILLMORE COUNTY. 273 



Topography.] 



situated within the river bluffs, so far below the general level of the country 

 that they can be seen but a short distance before reaching them. 



Further down Root river valley, the gorge in which the river runs be- 

 comes wider, being at Rushford about two miles in width, with fine farm 

 lands in the bottoms. The bluffs are rounded off with age and have a thin 

 soil, generally turfed, though showing frequent rock exposure. The river 

 is there 565 feet below the tops of the bluffs, as measured by aneroid. At 

 Whalen, in Holt township, the river is by the same measurement, 470 feet 

 below the top of the Trenton terrace on section 20. Whalen's bluff is 250 

 feet high above the river. At Lanesboro, in Carrollton, the river is 285 feet 

 below the immediate river bluffs, which consist wholly of the Cambrian for- 

 mations, and about 440 feet below the top of the Trenton terrace on section 

 20, Holt. At Preston the river at the stone mill is 335 feet below the Tren- 

 ton terrace, which forms the general level about a mile south of the village. 

 At Isinour's station the river runs 145 feet below the top of the Shakopee 

 limestone, which forms there the brow of the immediate river bluffs. At 

 Forestville the hight of the country north of the village, above the river, is 

 285 feet. The immediate river bluffs are 190 feet above the mill pond. At 

 Chatfield the river is about 222 feet below the general level of the country. 

 At Fillmore the prairie upland is 200 feet above the river level. From 

 Fountain to Isinour's station the track of the Southern Minnesota railroad 

 descends 401 feet, passing from the Galena to the St. Lawrence, and enter- 

 ing the latter formation about twenty-five feet, the rocks all lying nearly 

 horizontal. At Weisbach's mill, on Deer creek, section 11, Spring Valley, 

 the river is 205 feet below the general level of the country. There is here 

 a little drift, but the cut is mostly in the Galena and Trenton limestones. 

 The village of Fountain is about 350 feet higher than the terrace at Preston 

 on which the Stanwix House stands. These measurements might be mul- 

 tiplied, but enough have been given to show the uevenness of the surface 

 due to erosion. The rocks lie everywhere nearly horizontal. The varied 

 topography of the county is due to the influence of running water, and 

 atmospheric forces, on the rocks, combined with their alternations of lime- 

 stone with soft sandstone. The limestones are firm, and resist these forces 

 much longer than the sandstones. They alternate in the following manner 

 in descending order: 



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