EROSIONAL HISTORY OF DRIFTLESS AREA 61 



forming the summit areas are the sites of cities, towns, 

 villages, farms, wagon roads and railroads. In the Baraboo 

 district of Wisconsin there is an area more than two square 

 miles in extent so nearly flat that the drainage on its sur- 

 face is poor, and no spot is 10 feet higher or lower than the 

 general elevation of 1400 feet. In the southern portion of 

 the Sparta Quadrangle, Wisconsin, there is much flat land 

 at about 1335 feet A. T., more than 500 feet above main 

 drainage lines, on which are located the villages of New- 

 berg Corners, Middle Ridge and Portland (Fig. 12) » Here, 



Fig. 12. View of the summit ilain in the south portion of the Sparta Quadi-angle. 



in an area of 5 miles square there are approximately 7,000 

 acres of land under cultivation, supporting a prosperous 

 population of 4,500, all on flat-topped divides. From the 

 south edge of the Sparta Quadrangle a "ridge road" fol- 

 lows a continuous divide for more than 50 miles, passing 

 through the towns of Cashton, Rewey, Westby, Viroqua, 

 Seneca and Eastman, and leaves the crest of the ridge only 

 about a mile from the bluff of the Mississippi and two miles 

 from Prairie du Chien. In this distance the crest of the 

 divide has a relief of less than 100 feet, and the width of 

 the nearlv even crest varies from a few feet to a half mile 



