10 



Yearbook of the Department of Agriculture, 1921. 



Fig. 2. — The United States may be divided into two parts, equal in area, the East and 

 the West. The East has a humid climate, the West mostly an arid or semlarid climate, 

 except the North Pacific coast and the higher altitudes in the Sierra, Cascade, and Rocky- 

 Mountains. Each of these two parts has been subdivided into six agricultural regions, 

 characterized by distinct combinations of crops or systems of farming, the result largely 

 of the different climatic conditions. In tlie East these regions, with one exception, are 

 named after the crops : but in the West, because of the dominating influence of topog- 

 raphy and the Pacific Ocean upon the climate and the agriculture, topographic and geo- 

 graphic names are u.sed. (See pp. 7 to 9.) 



