Fig. 7. Blue Mountains, Umatilla National Forest, Washington, looking north-northeast across Al Williams Ridge to Tucannon River; 1933. (Forest Service photo, No. 4437.)
| Physiographic Provinces | Distributional Areas | ||||
| Cascade Mountains | { { | Cascade Mountains Yakima Valley | |||
| Puget Sound Willapa Hills Olympic Mountains | } } } | Western Washington | |||
| Okanogan Highlands | Northeastern Washington | ||||
| Columbia Lava | { { | Columbian Plateau Southeastern Washington | |||
| Blue Mountains | Blue Mountains | ||||
CLIMATE AND VEGETATION
The life-zone theory of plant and animal distribution was proposed by [Merriam] (1892). [Merriam]'s life-zones have been severely criticized by many authors, especially because an error was made in computing some of the data on temperature. However, zonation of vegetation and animals is obvious in Washington, and the life-zone concept has been employed in Washington by numerous botanists and zoölogists. Among them are: [Piper] (1906), [Taylor] and [Shaw] (1927), Jones (1936, 1938) and [St. John] (1937).
The higher parts of the Cascade Mountains are in the Arctic-alpine Life-zone. This is the area of wind-swept ridges, living glaciers, and permanent snow fields.
Trees are absent but a few shrubs are present; these include: Juniperus sibirica, Salix cascadensis, Salix nivalis, Gaultheria humifusa, Empetrum nigrum, and the heathers, Phyllodoce glanduliflora, Cassiope mertensiana and Cassiope stelleriana. Jones (1938) lists a total of 98 species of plants from the Arctic-alpine Life-zone of Mount Rainier. Many of these plants are most abundant in the next life-zone lower, and are of but incidental occurrence in the Arctic-alpine Life-zone. No mammalian species is resident but individuals of several species regularly visit and occasionally breed there.