The Western or Pacific forest extends two great legs, one down the Rocky Mountain Range, and the other along the Pacific coast. Between them lies the great treeless alkali plain centering around Nevada, Fig. 49. In these two regions coniferous trees have almost a monopoly. Broad-leaved trees are to be found there, along the river beds and in ravines, but they are of comparatively little importance. The forest is essentially an evergreen forest. Another marked feature of this western forest, except in the Puget Sound region, is that the trees, in many cases, stand far apart, their crowns not even touching, so that the sun beats down and dries up the forest floor, Fig. 50. There is no dense "forest cover" or canopy as in the Eastern Forest. Moreover these western forests are largely broken up, covering but a part of the mountains, many of which are snow-clad, and interrupted by bare plains. Along the creeks there grow a variety of hardwoods. It was never a continuous forest as was the Eastern Forest. The openness of this forest on the Rockies and on the eastern slopes of the Sierra Nevadas is in marked contrast to the western slopes of the Sierras, where there are to be seen the densest and most remarkable woods of the world, Fig. 51. This is due to the peculiar distribution of the rainfall of the region. The precipitation of the moisture upon the northwest coast where the trees are dripping with fog a large part of the time, is unequaled by that of any other locality on the continent. But the interior of this region, which is shut off by the high Sierra Nevadas from the western winds, has a very light and irregular rainfall. Where the rainfall is heavy, the forests are dense; and where the rainfall is light, the trees are sparse. [Illustration: Fig. 50. Open Western Forest, Bull Pine. Flagstaff, Arizona. _U. S. Forest Service._] Along the Rockies the characteristic trees are Engelmann's spruce, bull pine, Douglas fir, and lodgepole pine. As one goes west, the variety of trees increases and becomes, so far as conifers are concerned, far greater than in the east. Of 109 conifers in the United States, 80 belong to the western forests and 28 to the eastern. The Pacific forest is rich in the possession of half a dozen leading species--Douglas fir, western hemlock, sugar pine, bull pine, cedar and redwood. [Illustration: Fig. 51. Dense Forest of Puget Sound Region, Red Fir and Red Cedar. Pierce Co., Washington. _U. S. Forest Service._]