Nearly nine-tenths of the area of the park is under forest. Dense forests cover the moun tains up to an altitude of 9400 to 9700 feet, but on sonic of the basin floors there are scat tered open, park-like spaces covered with grass or incrustations front the hot springs. The forests are almost wholly coniferous, although liirches, willows, and poplars (Poidus tre»)u ion/cs) are not uncommon. The most common tree, and the only one monopolizing extensive forest areas, is the black pine Whims Mar rayana), and the second in distribution is the balsam (Abies subalpinu), chiefly confined to the higher and moister regions. Engelmann's spruce and the Douglas fir are also common, but the trees do not nearly reach the size attained in western Oregon and Washington, and the for ests can scarcely be called grand, though add in some places a remarkable charm to the scenery. The herbaceous vegetation is chiefly that of a mountain flora, though the sage brush occurs on some of the plateaus, and the alpine species above the timber line include nearly all of those common to the Rocky Mountains. The regions immediately surrounding the hot springs have a peculiar flora, partly resembling the xero phytes of the desert, partly allied to plants found on the seashore.
Owing to the protection afforded them, the wild animals in the park are increasing in num ber. Elk or wapiti abound, and can be seen iu large bands of several hundred or even thou sand: Moose, deer, antelopes, and mountain sheep can also be seen in winter, though in sum mer they generally retreat to the less frequented mountain regions. Until 1902 there were about 25 head of buffalo (bison) roaming wild in the park, but in that year 22, as many as could be found, were corralled, and 18 others were brought from distant parts of the country. It is the in
tention to improve the breed by this infusion of new blood, and, when the new herd becomes suf ficiently accustomed to the sight of human be ings, again to let them loose in the park. Mountain lions (pumas) were seen in the park in 1899, and bears. especially the black and the brown bear, are increasing in numbers. Beavers have also increased, and their dams and houses can be seen on the streams throughout the park. Birds are searre, almost the only game birds being a few blue and ruffled grouse. Trout of several varieties are so plentiful in nearly all the streams that with the existing regulations and the hatching and planting of many thou sand eggs annually, it will be impossible for the tourists to deplete them.
There is probably no region on earth of equal area which excels the Yellowstone Park in the variety of its natural scenery. For the exhi bition of the beautiful as well as of the grand and merely curious and interesting effects of volcanic forces the region has been unapproached since the destruction by a volcanic eruption of the White Terrace in New Zealand. Besides the two chief natural features described under sepa rate subheads below there are a number of minor objects of interest, such as cliffs of obsidian or volcanic glass along the shores of Beaver Lake, the petrified forests found on sonic of the pla teaus, and the curious freaks of erosion seen in the mushroom-shaped stone pillars in the 'Hoo doo Legion' and in the natural bridge spanning one of the creeks flowing into Yellowstone Lake.