face not too great for trees to be benefited by it. The upland areas 

 comprise the main part of the region. On them the tree roots never 

 reach water, which is often 100 to 200 feet below the surface. 



A sandhill region has more in common with the valleys than the 

 uplands, even when its situation is relatively high. Few people 



103 



102? 



100 



FIG. 1. Western Kansas and adjacent regions. 



realize how much moisture a sandhill soil contains. There is prac- 

 tically no surface run-off; all the water which falls sinks into the 

 ground. The soil never bakes, but is always in a receptive condition. 

 The evaporation is less than from a clay soil, and a larger percentage 

 of the moisture is available for plant use. The cottonwood and the 



[Cir. 181.] 



