10 



DRY FAEMII^G IN THE GREAT BASIN. 



The Great Salt Lake of Utah and a large depression in Nevada, 

 formerly occupied by Lake Lahontan, are the two most important 

 drainage centers, but there are numerous smaller lakes and sinks 

 quite independent of these. In addition to the agricultural land in 

 the Great Basin proper there is a considerable area of arable land 

 lying betAveen the eastern side of the Great Basin and the Rocky 

 Mountains. This constitutes the northern portion of the Colorado 

 Eiver drainage basin, but in view of the similarity of conditions pre- 

 vailing over this region and the near-by Great Basin it seems proper 

 to include both in a discussion of the agriculture of the section, and 

 in the present paper the term " Great Basin area " is used to include 

 not only the Great Basin proper, but also the region between it and 



the Eocky Mountains. By 

 far the larger part of the 

 arable land of the Great 

 Basin area lies at an alti- 

 tude of more than 4,200 feet 

 above sea level. The topog- 

 raph}'^ is broken by numer- 

 ous mountain ranges, so 

 that the arable land is con- 

 fined to the intervening val- 

 leys and wash plains. These 

 wash plains often occur as 

 high mesas, with a gently 

 rolling topography except 

 where they are cut by the 

 courses of streams and re- 

 cent erosions. 



The valleys of water 

 courses are now all more or 

 less developed by irriga- 

 tion, while the higher mesas which can not be reached by gravity 

 canals remain to be utilized without irrigation, if at all. 



In the eastern j^art of the Great Basin area, where most of the dry 

 farming is now done, the vallej^s and mesas are relatively small. One 

 or two of them are 15 or 20 miles across, but many are only 1 to 4 

 miles across and of varying lengths. Often they lie between high 

 timber-covered mountains that furnish perennial streams and a tim- 

 ber supply, as well as valuable range land. In other cases they are 

 surrounded by relatively barren hills, which afford neither water nor 

 timber and yield but little range. 



In the northern and central portions of this area the higher and 

 better-watered arable lands are covered with sagebrush {Artemisia 

 tridentata) with its gray-green foliage. In the swales on the roU- 



103 



Fig. 1.— Map showing the location of the Great Basin. 



