FORESTRY SURVEY 187 



nnder consuleratiou having but one or more of four types 

 of soil. In the order of their extent and influence on tree 

 growth these soil types, are as follows : A, yellow silt loam ; 

 B, yellow-gray silt loam ; C. the stony silt loam : D, brown 

 silt loam or prairie soil : E. black silt loam or alluvium ; F, 

 rock soil : G, sand : H, black muck. The first four com- 

 prise probably 90 per cent of the soils of Jo Daviess 

 county. Suppose that we take up a brief description of 

 these varieties of soil, in order. 



A Yclloir Silt Loam. — They ellow silt loam is the ex- 

 tensive soil occupying most of the elevated land and slopes 

 down to the usually abrupt declines bordering the immedi- 

 ate flowl-plains of the sti'eams. This soil is the chief farm- 

 land soil, and at least 50 per cent of the forest growth is 

 found upon it. By reason of its i)osition it is always more 

 or le.ss rolling or hilly, at times even abrupt, but is every- 

 where free from rock, usually, however, containing many 

 flint stones of small size. 



B^ Telloic-Graif Silt Lonm. — In a general way the yellow- 

 gray silt loam is found on the flat summit elevations of 

 nearly all the ridges between the lines of drainage. These 

 flat lands are commonly called "hardpan" and are notori- 

 ous for their i>oor drainage. It is here that all of the 

 ancient "buffalo wallows" are found. These are circular 

 ponds, forty to a hundred feet in diameter and from one to 

 three feet in depth, surrounded by a fringe of marsh, 

 caused by the buffalo of the early day standing in dense 

 numl>ei-s and gradually stamping out a depression that 

 became filled with water. These ponds were subsequently 

 used as drinking-places and as a refuge in hot weather 

 from the forest flies. So they were perpetuated until the 

 farmer drained them, as nuisances from his point of view. 



C, Stony Loam. — The stony loam occupies the steep 

 slopes adjacent to all the larger streams, and represents 

 the disiutegiated and brokeu-up rock exposures, covered to 

 a larger or smaller degree \rit\i the debris waslied down 

 from the adjacent elevate<l lands. The soil is usually dark 

 and very fertile, but so full of stones of all sizes as to be 

 totally unfit for cultivation. It is also invariably covered 

 with timber more or less cidled of better trees and. if used 

 at all as a farm asset, is devoted to pasturage. 



