NATURAL AREAS AND REGIONS 



225 



is only moderately affected. Absolutely 

 virgin conditions in this respect can be 

 found on the more remote parts of the 

 Idaho, Salmon, and Challis National 

 Forests. Hunting and trapping have 

 gone on for many decades and game 

 conditions are consequently below nor- 

 mal. The same is true of fishing. 



The foregoing description applies to 

 the region west of the Sawtooth Range 

 and along the Salmon River eastward as 

 far as Salmon City. To the west of 

 the Salmon Mountains in the region 

 covered by the greater part of the 

 Salmon, Challis, and Lemhi National 

 Forests the western yellow pine type 

 disappears, its place being taken by a 

 grass formation. Farther eastward the 

 Snake River plains become more and 

 more elevated and carry their sagebrush 

 formation directly to the lodgepole 

 pine and aspen {Populus tremuloides) 

 types in the mountains, virtually crowd- 

 ing out the grass tj'pe which appears 

 farther west. In the Targhee National 

 Forest of Idaho as w^ell as in the Teton 

 and Wyoming National Forests of 

 Wyoming, virgin stands of lodgepole 

 pine characterize the mountains. These 

 extend to the lowest slopes of the moun- 

 tains. The higher elevations are cov- 

 ered with stands of alpine fir and Engel- 

 mann spruce, the same being true indeed 

 of all the forests throughout this region. 

 Very little cutting has been done in any 

 of these and grazing is generally light to 

 moderate. In the Teton National for- 

 est especially in the neighborhood of 

 the Yellowstone National Park game 

 conditions are practically unaffected 

 by the activities of man. In the Cari- 

 bou National Forest a change begins 

 to appear. The timber types become 

 broken and scattered, interspersed with 

 large areas of open country and the 

 aspen begins to assume a prominent 

 place. The valleys between the ranges 

 are high, so that lodgepole pine and 

 aspen extend to the foot of the moun- 

 tains. The higher summits and north- 

 ern slopes bear stands of alpine fir and 

 Engelmann spruce. Conditions are 

 similar on the Cache National Forest in 



Utah, although here in main valleys 

 become lower and a brush type made up 

 largely of mountain mahogany (Cerco- 

 carpus pariifolius), dwarf oak (Quercus 

 utahensis), skunk-bush (Rhus trilobala) 

 and chokecherry (Prunus demissa), is 

 found between the lower parts of the 

 lodgepole pine and Douglas fir types and 

 the agricultural valleys. Farther south 

 this brush holt becomes wider, and is 

 largely dominated by scrub oak (Quercus 

 utahensis). Lodgepole pine is less prom- 

 inent and aspen becomes more con- 

 spicuous. South of the headwaters of 

 the Provo River on the Uinta National 

 Forest lodgepole pine drops out entirely. 

 On the Manti National Forest the 

 altitudinal succession of types is ex- 

 tended by the appearance of a well 

 developed pinyon-juniper type below 

 the brush belt and above the agricul- 

 tural valleys, making the succession; 

 sagebrush (largely under cultivation), 

 pinyon-juniper, brush, aspen-Douglas 

 fir, and lastly spruce-fir. On the higher 

 elevations are many open grassy mea- 

 dows. Eastward from the Wasatch 

 and Uinta National Forests, on the 

 Uinta Mountains conditions again be- 

 come somewhat different. On the Ash- 

 ley and parts of the Uinta National 

 Forest, lodgepole pine is prominent at 

 high elevations. Toward the east end 

 of the Ashley National Forest at lower 

 elevations, adjoining the sagebrush, the 

 western yellow pine tj'pe reappears. 

 Southward from the Manti National 

 Forest in Utah, the Fishlake and Fill- 

 more National Forests present similar 

 aspects. On the Powell and Dixie 

 National Forests, the western yellow 

 pine again reappears taking the place 

 of the brush type farther north. The 

 pinyon-juniper type is very well de- 

 veloped at the lower elevations. The 

 Kaibab National Forest in northern 

 Arizona consists of a plateau covered 

 primaril}' with western yellow pine 

 encircled by an escarpment bearing an 

 open stand of pinyon and juniper. On 

 the National Forests of Nevada the 

 pinyon-juniper anil brush types are 

 common and the arborescent flora is 



