The Coast Ranges, although generally bare of trees to the south of the Golden Gate, become more and more densely forested when followed northward. It is in this northern division that the great forests of redwood occur, now so largely used for lumber. Reference is here made not to the "big trees," which grow in certain restricted areas on the west slope of the Sierra Nevada, but to the far more extensive forests of a related species. Considering mountain forms simply, it is difficult if not impossible to determine where the Coast Mountains of California terminate at the north, but, as has been shown especially by J. S. Diller, there are reasons based on geological structure for separating them from the irregular group of ranges and peaks in northern California and southern Oregon recently named the Klamath Mountains. The coast system is continued north of the Klamath Mountains by the Coast Mountains of Oregon, which extend to the Columbia River, and consist of irregular ridges or series of ridges, with bold lateral spurs, especially on the ocean side. It varies conspicuously in height from place to place, yet nowhere attains a great altitude. The elevations of the bolder summits, although not accurately measured, seldom exceed 3,000 feet. The Coast Mountains of Oregon are considered as terminating at the northern boundary of the State, there defined by the Columbia River, but no reason is apparent, however, for not including in the same group the elevated land lying in southwestern Washington and adjacent to the Pacific coast. Between the Columbia and Chehalis River in Washington there is a rugged region which attains an elevation of over 4,000 feet, and is separated from the Olympic Mountains to the northward by Chehalis Valley. Although the geology of this group of ridges and peaks is entirely unknown, its position and general appearance, when seen from a distance, suggest that it might properly be considered as a direct extension of the Coast Mountains of Oregon. Following the general belt of the Coast Ranges still farther northward, we come to the splendid group of forest-clothed mountains, with usually snow-covered summits, situated to the west of Puget Sound, and known as the Olympic Mountains. This magnificent range is in full view from Victoria, Seattle, and Tacoma, and would be far-famed for its grandeur were it not for its near rival, the still more lofty Cascade Range.