12 FORAGE CONDITIONS ON NORTHERN" BORDER OF GREAT BASIN. 



DESCRIPTION OF THE REGION. 



The greater portion of the area studied is situated in the Great Basin, 

 and nia}^ be briefly and tersely described as a series of basins along 

 the border of this large arid region, which receives less than 10 inches 

 of moisture during the entire twelve months. 



As would be expected, the transition from the Great Basin to the 

 headwaters of the Columbia River is a very slow and gradual one, 

 and the remarks which follow, while dealing especially with the por- 

 tion of the Great Basin visited, apply in general to that portion of the 

 Columbia River drainage which lies contiguous to it on the north. 

 The main basins visited were the Alvoid Desert and the basin of the 

 Malheur and Harney lakes. A glance at the map will show that even 

 the river valleys are in effect basins, for they almost invariabl} r empty 

 into "sinks" (broad, level areas) over which their waters spread and 

 evaporate early in the summer, leaving a broad expanse of gra} T ish 

 white soil with no vegetation and often deeply fissured, as shown in the 

 lower portion of PI. VII, fig. 1. The Quinn Kiver Valley is simply a 

 portion of the large Black Rock Desert basin, and a section of it in 

 the vicinity of Quinn River Crossing does not differ materially from 

 a similar section of the basin of the Alvord Desert. 



These level desert bottoms receive considerable water in the spring 

 of the year from melting snows on surrounding mountains. The 

 Alvord Desert, it is said, is usually a lake varying from a few inches 

 to a foot or two in depth at this season, the depth varying greatly, 

 however, from day to day in the different portions of the bed, depend- 

 ing upon the direction and velocity of the wind. Surrounding these 

 areas, many of which are entirely devoid of vegetation during the 

 entire } 7 ear, while others less pronounced have scattering growths of 

 iodine weed {Spirostachys occidentalis) and scattering bunches of 

 greasewood {Sarcobatus vermicidatas), is found a zone of greater or 

 less extent — a few feet to several rods or even a mile in some cases — 

 of salt grass {Distichlis spicata). Beyond this the greasewood again 

 predominates, but often gives place in certain localities to the ra}dess 

 goldenrod — the rabbit brush of the region {Chrysothamnus graveo- 

 leris). Beyond the greasewood belt the soil is less alkaline, as shown 

 by the presence of the black sage {Artemisia tridentata), which extends 

 from here through the ravines and other depressions up into the 

 mountains. On the lower foothills between the ravines, in which the 

 black sage is the characteristic plant, the spiny saltbush {Atriplex 

 con fertif olid) , hop sage {Grayia spinosa), and bud sage {Artemisia 

 spinescens) are usually the conspicuous plants, especially in northern 

 Nevada. The latter are less conspicuous to the northward. Indeed, 

 we saw but very little of the three last named after leaving the Alvoid 

 Desert until we reached the main stream of the Malheur River near 

 the Harper Ranch, 40 miles above Ontario, Oreg. 



