50 BULLETIN 618, U. S. DEPARTMENT OF AGRICULTURE. 



Cascade Ranges, excluding the humid portions of northern Idaho 

 and northern Washington. The semiarid coastal area comprises 

 only the two great interior valleys of California. The Willamette 

 Valley of Oregon and the Puget Sound section of Washington are 

 humid. 



The chief agricultural lands of the basin area mostly He at alti- 

 tudes of 4,000 to 6,000 feet. This includes most of the dry-farmed 

 districts in Utah, Idaho, Nevada, and Oregon, often called the 

 Great Basin. It comprises the Salt Lake Basin of Utah, the Snake 

 River Basin of Idaho, the Humboldt Basin of northern Nevada, 

 the Harney Basin of southeastern Oregon, and the plateau region of 

 central and southern Oregon, as well as territory adjacent to but 

 perhaps not strictly included in any of these. The Columbia Basin 

 of eastern Washington and north-central Oregon has an altitude of 

 1,000 to 2,000 feet. The San Joaquin and Sacramento Valleys of 

 California lie much lower, the lower end of each reaching sea level 

 and the upper portions being but a few hundred feet higher. 



All these areas are characterized by low precipitation. Most of 

 the rain falls during the autumn, winter, and spring months instead 

 of during the summer, as in the Great Plains area. The seasonal 

 rainfall is small in proportion to the total precipitation. For this 

 reason, among others, winter wheats are more profitable and more 

 extensively grown than spring-sown wheats. Crop production is 

 governed almost wholly bj the quantity and distribution of the 

 annual precipitation. From Table II it will be seen that the annual 

 rainfall of these stations, omitting only Chico, Cal., ranges from 9.5 

 to 13.5 inches. 



Summer fallowing the land or allowing the fields to lie fallow in 

 alternate years is the common farm and station practice in these 

 areas. Summer tillage of the fallow to prevent the growth, of weeds 

 and volunteer grain conserves much of the moisture which falls in 

 the year of fallow to help grow the crop in the succeeding year. 



The soils of much of this area are of volcanic origin and are light 

 in texture. Reference again to the data in Table II shows the soil 

 at all six of the stations named to be either a sandy loam or a sandy 

 clay loam. 



Owing to the altitude, the growing season is short in much of this 

 territory and early varieties are desirable. This also is another 

 reason why winter varieties are more satisfactory. Even in the 

 California valleys, with their low altitude and extremely long grow- 

 ing season, the intense heat and drought of midsummer make early 

 varieties as important there as elsewhere. 



The results from six stations in the arid basin and coastal areas are 

 given in this bulletin. These stations are well scattered geograph- 



