CHAPTER IV 
DRY-FARM AREAS.— GENERAL CLIMATIC FEATURES 
Tue 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, cafions, 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 Cafion of the Colorado. 
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