NATURAL AREAS AND REGIONS 



173 



Rocky Mountain goat {Oreamnos ameri- 

 canus). The extensive talus slopes are 

 the habitat of the marmot and pika. 

 The marmot [Marmola ohjm'pus) is also 

 found in the higher altitudes of the 

 Olympic Mountains. 



6. BUNCH GRASS PRAIRIE 



(The bunch grass community with 

 the western yellow pine community 

 makes up Merriam's Arid Transition 

 Zone.) 



a. Plants. The bunch grass area is 

 quite extensive and is bordered above 

 by the western yellow pine forest and 

 below by the sagebrush area. It oc- 

 cupies portions of Okanogan, Douglas, 

 Lincoln, Spokane, Adams, Whitman, 

 Walla Walla, Columbia, Garfield and 

 Asotin counties. It is grass covered 

 and mostly treeless. Willows (Salix 

 spp.), haw {Crataegus brevispina) , aspen 

 and Cottonwood (Populus trichocarpa) 

 are the principal trees and are found 

 mostly along streams and around 

 springs. Undershrubs are snowberry 

 (Symphoricarpos racemosus) , roses (Rosa 

 nutkana and R. pisocarpa) , gooseberries 

 (Ribes inerma and R. irriguwn) and 

 a low birch (Betula microphylla) . 

 Bunch grass (Agropyron spicatum) is 

 the most characteristic plant of this 

 community. Other plants are June 

 grass {Poa sandbergii), lupines (Lupinus 

 ornatus, L. sericeus and L. wyethii), 

 sunflowers {Helianthella douglasii and 

 Balsamorhiza sagittata), and Indian 

 paint brush [Castilleja miniota). The 

 vegetation in this area is frequently 

 more luxuriant on north slopes than on 

 south. 



b. Animals. Some of the characteris- 

 tic forms of the bunch-grass of eastern 

 Washington are the coyote, mountain 

 weasel (Mustela arizonensis) , skunk 

 {Mephitis occidentalis major), badger 

 {Taxidea taxus neglecta), pocket-mouse 

 {Perognathus), pocket-gopher, ground- 

 squirrels, and white-tailed jackrabbit 

 {Lepus townsendii) . In the willow and 

 Cottonwood timber along the streams 

 occur a number of other forms, such as 

 the shrew {Sorex vagrans dobsoni), 



mink {Mustela vison energumenos) , har- 

 vest-mouse {Reithrodontomys megalotis 

 nigrescens) , deer-mouse, muskrat (Onda- 

 tra zibethica osoyoosensis), and beaver 

 (Castor)— L.ll.D. 



The bull-snake is the most conspicuous 

 reptile of the bunch grass areas. Here 

 also occur the racer and the skink 

 (Eumeces sMltonianus) . The garter- 

 snake {Thamnophis a. ordinoides) the 

 western toad, the leopard-frog (Rana 

 pipiens), the western tree-frog (Uyla 

 regilla), and the pond-turtle (Chrysem,ys 

 bellii bellii) occur chiefly along streams. 

 — H. T. G. 



7. Sagebrush semi desert (see also in 

 British Columbia and Oregon 

 accounts) (Upper Sonoran Zone) 



a. Plants. This community is almost 

 wholly included within a line surround- 

 ing the Columbia basin below an eleva- 

 tion varying from 1200 to 1700 ft. depend- 

 ing upon slope and precipitation. 

 Where the elevation exceeds 1700 ft. 

 or the rainfall about 12 in. sagebrush 

 gives way to bunch grass. The annual 

 precipitation of this basin, as is typical 

 of such districts, is low, ranging from 

 6 to 12 in. 



Sagebrush is the most conspicuous 

 plant of the area, though according to 

 Piper, there are frequently found rabbit 

 brush, hop sage (Grayia spinosa), 

 antelope brush (Kunzia tridentata) , and 

 in alkaline situations, greasewood. 

 There also occur frequent and character- 

 istic patches of prickly pear (Opuntia 

 polyoantha). The sagebrush often 

 reaches a height of from 8 to 12 ft., and 

 becomes a veritable thicket, though in 

 some localities it does not become more 

 than a few inches high. The appearance 

 of an extensive sagebrush plain is that 

 of a desert waste. Another feature of 

 the sagebrush district is the occurrence 

 here and there of dunes of drifting sand. 

 In some places these dunes practically 

 wipe out all forms of vegetation as they 

 march on their age-long journey. In 

 their march, however, they are closely 

 followed by the ever-present sagebrush. 

 Along the coulees, on the hills which 



