UNITED STATES OF AMERICA 



UNITED STATES OF AMERICA 



which has already become an article of export 

 to Europe. 



Mountain States. On the Cordilleran high- 

 land (see CORDILLERA) from the Rocky Moun- 

 tains to the Sierra Nevada-Cascade range, the 

 soil is usually fertile, and much of it is suffi- 

 ciently level to be used for farming, but the 

 rainfall over most of this immense region is 

 insufficient. In the Southwest, indeed, there 

 are some patches of true desert. In the North- 

 west, on the other hand, the lower temperature 

 and stronger west winds cause a heavier rain- 

 fall. There, too, the Columbia River gap ad- 

 mits the moisture-laden winds to the plateau, 

 helping to water the splendid wheat district 

 around Spokane. There are also some other 

 districts which have sufficient rainfall, but in 

 general water must be brought to the land 

 artificially or there will be no harvest. As a 

 result, land alone is worthless, but water is 

 almost priceless. 



Owing in part to these climatic conditions, 

 stock raising and mining have always been the 

 leading industries on the Cordilleran highland. 

 Originally cattle predominated, but in recent 

 years sheep raising has become more and more 

 prominent. This has injured the cattle raising 

 industry, since sheep crop the grass so close 

 to the roots that cattle cannot graze after them. 

 Much of the land has thus been overgrazed, 

 with the result that a good deal of it cannot 

 now support as many head of live stock to the 

 thousand acres as it could thirty years ago. 

 The Cordilleran highland is, however, the prin- 

 cipal wool growing section of the United States. 



Irrigation and Dry Farming. In order to de- 

 velop farming, private corporations first under- 

 took to construct dams and irrigation ditches, 

 naturally choosing the most favorable situa- 

 tions. Later the United States government 

 made a grant of land to the states in aid of 

 irrigation, and finally undertook directly the 

 construction of irrigation works. It is esti- 

 mated that eventually over fifty million acres 

 of land may be irrigated in the valleys and at 

 the foot of the mountains, where water may be 

 delivered by gravity. There is also a possibility 

 of pumping water from the rivers to some of 

 the higher levels, but this plan is too expen- 

 sive for general use. Such a development of 

 irrigation will mean the creation in the midst 

 of the desert of many densely-peopled farming 

 communities. In 1917 about 14,000,000 acres 

 were irrigated, not including rice fields, for 

 which more than 14,000 pumping plants were 

 required. The approximate acreage in each 



state, the number of farms served and the cost 

 of construction appear in the following table; 

 in the article IRRIGATION are descriptions of 

 some of the greatest of the country's irrigation 

 projects: 



In addition to irrigation farming, it has been 

 found possible in recent years to grow certain 

 crops by a process known as dry farming 

 (which see). West of the Rocky Mountains 

 the rain, falling chiefly in winter, is absorbed 

 into the soil without much evaporation, and 

 over a large part of the area the surface -soil 

 is underlaid by clay, which is almost impervious 

 to water. These two facts are taken advantage 

 of to grow a crop every other year by keeping 

 the surface covered during the intervening 

 summer with a coating of finely-pulverized soil 

 which checks evaporation and thus stores the 

 rain of two winters in the soil. This plan 

 makes it possible to grow wheat and some other 

 staple crops with as little rain as ten to twelve 

 inches a year. 



The leading crops on the Cordilleran high- 

 land are wheat and alfalfa, a plant related to 

 clover, which is grown for hay. Owing to the 

 dry summer, the grain dries on the stalk so 

 thoroughly that it can be cut, threshed and 

 sacked by one machine, thus saving labor and 

 leaving the stalks in the field to fertilize the 

 soil. Vegetables are also grown, especially 

 potatoes and sugar beets in Colorado. 



Pacific Slope. On the Pacific slope agricul- 

 tural conditions are much the same as in the 

 Cordilleran section, except in the region of 

 abundant rainfall around Puget Sound. The 

 leading grain crops are wheat, in California, 

 also barley, which takes the place of corn as a 

 food for stock. Sugar beets and lima beans are 

 also of considerable importance in Southern 



