48 DRY LAND FARMING 



of various localities in the Great Plains area in the almost 

 entire absence of elevations of any great prominence. 

 For instance, the normal precipitation at Chester, Mont., 

 would appear to be considerably less than that of areas to 

 the east and west. 



Speaking in a general way, it would be correct to 

 say that the semi-arid and arid regions of the United 

 States and Canada lie between the meridians of 100 and 

 120 west longitude and between the parallels of 51 to 

 53 and 30 respectively north latitude. This immense 

 area comprises approximately 1,400,000,000 acres. 



The line which bounds the area on the east where 

 the rainfall is not more than -20 inches is as follows : It 

 begins in the northeastern part of North Dakota, not 

 very far distant from the Red river, and bears slightly to 

 the southwest until it reaches the Mexican border. This 

 line cuts off to the westward more than three-fourths 

 of North Dakota, about two-thirds of South Dakota, 

 about one-third of Nebraska, about one-fourth of Kansas 

 and Texas, and a small portion of Oklahoma. The line 

 that bounds it on the west runs virtually not far distant 

 from the western base of the Cascade and Sierra Nevada 

 mountains, except in certain areas of California, where 

 it runs still farther to the west. 



The states included in the dry belt in whole or in 

 part, are the following: North Dakota, South Dakota, 

 Nebraska, Kansas, Oklahoma, Texas, New Mexico, Colo- 

 rado, Wyoming, Montana, Idaho, Nevada, Arizona, Cali- 

 fornia, Oregon and Washington, seventeen in all. East- 

 ern North Dakota, South Dakota, Nebraska, Kansas, 

 Oklahoma and Texas lie within the areas classed as sub- 

 humid and humid, and the same is true of the western 

 portions of California, Oregon and Washington. In 

 parts of Colorado, New Mexico, Arizona, Utah, Wyom- 

 ing, Washington, Oregon, Nevada and Lower California, 

 the annual precipitation is less than 10 inches. In but a 



