GRASS-CROP AREAS 83 



With proper care in preparation of the soil and in seeding, 

 this leguminous crop can be grown without irrigation over 

 a very considerable portion of the area. 



114. The arid region. — This includes all the region 

 west of the Great Plains where the rainfall is insufficient 

 for the growth of crops without the aid of irrigation. 

 Besides the two main mountain systems, the Rocky 

 Mountains and the Sierra Nevada, there are numerous 

 smaller ranges throughout the region between. The term 

 Great Basin strictly applies to that portion such as most 

 of Utah and Nevada which has no drainage to the sea. 

 This name is often applied in a loose way to the whole 

 region between the two mountain systems mentioned. 

 The general level of this interior region is at 4,000 to 5,000 

 feet altitude. Usually at higher altitudes in the mountains 

 the climate is increasingly moist. Above about 8,000 

 feet the climate is usually humid and the slopes are in 

 general more or less forested. 



The climate of the plains and valleys is arid. Crops 

 are raised only as water for irrigation can be obtained from 

 the streams. Much of the area is sufficiently arid to be 

 called a desert. This is especially so in the southern part 

 where the summers are longer. Under favorable conditions 

 crops can be raised by applying the methods of dry-land 

 farming. Such may be the case at the base of a mountain 

 slope where there is sub-irrigation through seepage from 

 the mountain. The great proportion of this arid region 

 is used for stock-grazing in so far as it can be used at all 

 for agricultural purposes. Most of the grazing is in the 

 mountains but there is some forage on the desert which is 

 utilized if water for stock is available (Par. 20). Where 

 there is snow in winter, sheep can be pastured, the animals 

 depending on the snow for their water-supply. 



