1 CULTIVATED FORAGE CROPS OF THE NORTHWEST. 
whose cultivation should be extended. Among these may be men- 
tioned the Canada field pea, rape, and awnless brome grass. 
GREAT BASIN. 
This region extends from the Sierra Nevada Mountains to the Rocky 
Mountains, and from Arizona north into southeastern Oregon and 
southern Idaho. It is an arid region, having an annual rainfall of 
less than 15 inches over the greater part, and in central Nevada of 
less than 5 inches. The altitude of this great plateau is about 5,000 
or 6,000 feet, with numerous mountain chains rising 2,000 or 3,000 
feet higher. ‘There are several lakes or depressions having no outlet, 
the largest of which is the Great Salt Lake of Utah. 
In such localities there is usually an excessive accumulation of min- 
eral salts, known as alkali. The water of the streams flowing into 
these depressions holds these salts in solution, but deposits them upon 
the surface of the soil when the water evaporates. These alkali soils 
modify the vegetation. Each species of plant is able to withstand a 
certain amount of alkali in the soil upon which it grows. If the amount 
is in excess of this limit, the plant can not exist. Consequently, the 
native vegetation gives a fair index of the alkaline condition of the 
soil. The presence of saltbushes (Atriplex spp.), salt grass (Déstichlis 
spicata), and grease wood (Sarcobatus vermiculatus) indicates a strongly 
alkaline soil. A still larger amount of soluble mineral matter prevents 
the growth of even the salt plants, and in such cases the soil is devoid 
of vegetation. 
The prevailing vegetation over the whole region, except in the 
mountains and upon the above-mentioned alkali soils, is the sagebrush 
(Artemisia tridentata). Hence such localities are called sagebrush 
plains. As in the case of the two preceding areas the chief agricul- 
tural industry is the raising of stock—cattle, sheep, and horses. The 
latter class of stock is of importance in certain localities, but is rela- 
tively unimportant over the whole area. The sheep are herded in the 
mountains in summer, where there is water, and upon the deserts in 
winter, where there is snow. There are vast areas where stock can 
not graze on account of the insufficiency of food or water, or both. 
Alfalfa is grown in large quantities under irrigation in the valleys 
and is practically the only supplemental forage for all kinds of stock. 
In some of the larger valleys other crops are raised, such as grain and 
sugar beets. As an example, the highly cultivated Cache Valley, in 
northern Utah, may be mentioned. In a few favored localities dry 
farming may be carried on successfully. This, however, is where 
there is seepage and conservation of water from the winter snow on 
the mountains. In the Cache Valley there are numerous instances of 
grain and alfalfa fields on the hillsides above the canals. 
