NATURAL AREAS AND REGIONS 



185 



and the corresponding increase in 

 moisture. 



The yellow pine forest is the semi- 

 desert or xerophytic coniferous forest. 

 The forest floor is characterized by 

 snow bush (Ceanothus velutinus), ante- 

 lope bush, manzanita, and Idaho fescue 

 (Festuca idahoense). 



It is well known that the herbaceous 

 and shrubby vegetation varies with the 

 type of forest. On account of the large 

 territorial area and the varying climatic 

 and soil conditions, it is impossible to 

 accurately picture the smaller vegeta- 

 tion that accompanies the larger. The 

 mesophytic coniferous forest is the 

 habitat of the following: Snowbush, 

 thimble berry, huckleberries (V ac- 

 tinium), naked rose (Rosa gymnocarpa), 

 twin berry (Lonicera involucrata) , 

 Prince's pine (Chimaphila umbellata), 

 twin flower (Linnaea americana), colum- 

 bine (Aquilegia formosa), false bugbane 

 (Trautvetteria grandis) and species of 

 currants and gooseberries. 



Alpine meadows in both the Blue and 

 Cascade Mountains may be found at or 

 near timber line on the gentle slopes 

 and valleys. But the rocky ridges and 

 peaks are more or less covered with 

 scattered white bark pine (Pinus albi- 

 caulis), mountain hemlock, and various 

 shrubs. Following the recession of 

 snow, alpine erythroniums, and anem- 

 ones may be found. 



B. Animal communities illustrated by 

 mammals (H. M. W.). The divide of 

 the Cascade Mountains separates Oregon 

 into two areas, Western and Eastern 

 Oregon. Western Oregon is again cut 

 by the Coast Range Mountains leaving 

 the big valleys of the Willamette, the 

 Umpqua and Rogue Rivers, lying be- 

 tween the two ranges. 



The areas of Western Oregon recog- 

 nized in this paper are, the Moist coni- 

 ferous forests of two slopes of the Coast 

 Range Mountains; the Valley prairie 

 areas of the Willamette, Umpqua and 

 the Rogue River, the Hill prairie areas 

 comprising the foothills of the two 

 mountain ranges rising out of the val- 

 leys; and the moist coniferous forests 



situated throughout the west slope of 

 the Cascade Mountains. 



The areas of Eastern Oregon con- 

 sidered are, the Semi-desert coniferous 

 forests of the Eastern slope of the 

 Cascades; the Coniferous forests of the 

 Blue Mountains; the Bunch grass prairie 

 lying between the Blue Mountains and 

 the Cascades in the North, and drained 

 by the Deschutes, John Day and Umatilla 

 rivers; and the big Sage brush desert 

 lying south of the Blue Mountains and 

 Bunch grass prairie. 



The flora of Oregon is not as greatly 

 changed from its original condition as 

 is its fauna. Few mammals 4 have been 

 entirely exterminated, but the distribu- 

 tion of many has become restricted, and 

 the numbers of nearly all show evidence 

 of decrease. Within the great conifer- 

 ous forests of Oregon and throughout the 

 arid section of the Sagebrush desert in 

 the southeastern corner of the state, and 

 extending into Idaho and Nevada, the 

 biota has been remarkably well preserved. 



The west slope of the Coast Range 

 Mountains. Luxuriant open valleys 

 within this stand of timber furnished 

 forage for thousands of western wapiti 

 or elk (Cervus c. occidentalis) . The 

 black-tailed deer (Odocoileus columbi- 

 anus) fed within the jungles of Salal, 

 which carpeted this virgin forest. The 

 black bear stripped the huckleberry, and 

 the chittim (Cascara) berries, and 

 caught the fish from the numerous 

 streams which drain the west slope into 

 the Pacific Ocean. These streams were 

 followed by the western raccoon 

 (Procyon psora pacifica), the Pacific 

 mink, the Pacific otter (Lutra canadensis 

 pacifica). The Pacific beaver (Castor 

 canadensis pacifica) were abundant as 

 were in some sections, the Oregon coast 

 muskrat (Fiber zibethica occipitalis) . 

 The Puget Sound skunk and the spotted 

 skunk (Spilogale phenax latifrons) were 

 present. The hillsides were pentrated 

 by the mountain beaver (Aplodontia 

 rufa pacifica). 



4 Scientific names of mammals mentioned in Brit- 

 ish Columbia and Washington do not occur in 

 Oregon account. 



