26 
BULLETIIT 1348, U. S. DEPARTMENT OF AGKICULTTJEE 
Fig. 26.— The United States may be divided into two parts, equal in area, the East and the West. 
The East has a humid dimate, the West mostly an arid or semiarid climate, except the North Pa- 
cific 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 combina- 
tions of crops or systems of farming, the result largely of the dilTerent climatic conditions. In the 
East these rccjions, with one exception, are named after the crops; but in the West, because of the 
dominating iiitluence of topotiraphy and the Pacific Ocean upon the climate and the agricul- 
ture, topograptiic and geographic names are used. (U. S. Dept. Agr. Yearbook 1921.) 
