Fig. 52. Virgin Forest of Red Fir, Red Cedar, Western Hemlock, and Oregon Maple. Ashford, Washington. U. S. Forest Service.

Fig. 53. Redwood Forest. Santa Cruz Co., Calif. U. S. Forest Service.

The big tree, Fig. 54, occurs exclusively in groves, which, however, are not pure, but are scattered among a much larger number of trees of other kinds.

Fig. 54. Big Tree Forest. Sierra National Forest, California. U. S. Forest Service.

The great and unsurpassed Puget Sound forest is destined to be before long the center of the lumber trade of this country.

These two great forests of the east and the west both run northward into British America, and are there united in a broad belt of subarctic forest which extends across the continent. At the far north it is characterized by the white spruce and aspen. The forest is open, stunted, and of no economic value.