CHAPTER IV 



DRY-FARM AREAS. — GENERAL CLIMATIC FEATURES 



The dry-farm territory of the United States 

 stretches from the Pacific seaboard to the 96th parallel 

 of longitude, and from the Canadian to the Mexican 

 boundary, making a total area of nearly 1,800,000 

 square miles. This immense territory is far from 

 being a vast level plain. On the extreme east is the 

 Great Plains region of the Mississippi Valley which 

 is a comparatively uniform country of rolling hills, 

 but no mountains. At a point about one third of 

 the whole distance westward the whole land is lifted 

 skyward by the Rocky Mountains, which cross the 

 country from south to northwest. Here are innu- 

 merable peaks, caiions, high table-lands, roaring 

 torrents, and quiet mountain valleys. West of the 

 Rockies is the great depression known as the Great 

 Basin, which has no outlet to the ocean. It is 

 essentially a gigantic level lake floor traversed in 

 many directions by mountain ranges that are off- 

 shoots from the backbone of the Rockies. South 

 of the Great Basin are the high plateaus, into which 

 many great chasms are cut, the best known and 

 largest of which is the great Caiion of the Colorado. 



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