West of the Canadian Life-zone in the western Cascades, the coniferous forests merge with the lowland forests of western Washington. To the east of the Canadian Life-zone in the eastern Cascades, there is a distinct change to a more arid climate and flora. At Leavenworth, 1167 feet, Chelan County, the annual average precipitation is but 19.5 inches and at Cle Elum, 1930 feet, but 23.23 inches. Temperatures are higher, the annual average of the above two localities being 47.2° and 45.4° respectively. The winter months are cold, with the average temperature in January and February below freezing. In summer the averages in July and August at Leavenworth are 68.8° and 68.0°, with the average maximum being 87.5° and 86.1°. Snowfall is heavy, the yearly average at Leavenworth being 98.5 inches and at Cle Elum 86.3 inches. The effect of this more arid climate is seen in the vegetation. The dense Douglas fir forest, is replaced by more open forests of yellow pine (_Pinus ponderosus_). Groves of oak (_Quercus garryana_) are found near streams. The open forests give way to the extensive grasslands bordering the desert. The transition of vegetation is similar to that occurring in the Yakima Valley Area. In the Yakima Valley Area, arid conditions prevail. The average yearly precipitation at Yakima is 6.67 inches. Only in November, December and January may more than one inch of precipitation be expected monthly. Snow may be expected in the winter months and the yearly average snowfall is 22.1 inches. Winter temperatures are low, the average for December and January being but slightly above freezing. Summer temperatures are extreme; the July average is 73.1° and the average maximum for the same month is 89°. The highest temperature recorded is 111°. The open pine forests of the eastern Cascades give way to grasslands. Grasses of several species are common but the bunchgrass (_Agropyron spicatum_) is most important. Other plants include the primrose (_Oenothera pallida_), lupines (_Lupinus_), and _Mertensia_. In ravines and near watercourses such shrubs as hawthorn (_Crataegus douglasii_), service-berry (_Amelanchier cusickii_, _Amelanchier utahensis_), aspen (_Populus tremuloides_), syringa (_Philadelphus lewisii_), snowberry (_Symphoricarpos albus_), choke-berry (_Prunus melanocarpa_) and elderberry (_Sambucus caerulae_) form thickets. Lower in the valley the vegetation is xerophytic, similar to that of the Columbian Plateau. Sagebrush (_Artemisiae tridentata_) is dominant. Other shrubs include rabbit brush (_Chrysothamnus nauseosus_, _Chrysothamnus viscidiflorus_), hop sage (_Grayia spinosa_), black sage (_Purshia tridentata_) and greasewood (_Sarcobatus vermiculatus_). [Illustration: FIG. 9. Mount Rainier. Washington: Cowlitz Chimneys from base of Dege Peak, July 19, 1933. (Fish and Wildlife Service photo by Victor B. Scheffer, No. 859.)]