SOIL RELATIONS 



241 



tions of other mountain states. However, as in the cher- 

 nozem, there is an approach to perfect prairie soils from 

 the forest lands westward, and the arid lands eastward, 

 up to about the meridians 95 to 98. In Canada the 



FIG. 74. Map showing very roughly the extent of the Great Plains m 

 the United States and Canada. 



prairie region lies between the 96th and 114th meridians, 

 and narrows rapidly northwestward, reaching as far as 

 the Saskatchewan River, but in Alberta, not much beyond 

 the Battle River (Fig. 74). Taking into account the factor 



