FOREST TREES OF THE PACIFIC SLOPE. 115 



on Sauk River near Monte Cristo : head of Early Winter Creek. Both sides of Cascades 

 in southern Washington National Forest, in valleys of Skykomlsb, Tolt, Snoqualmie, 

 Green, White. Yakima. Wenache, and Entiat rivers, up to an elevation of .".too feet. 

 Noted in Wenache Mountains and range between Columbia River and Yakima River, 

 at ."..000 feet. Mount Ilainier National Forest, both sides of range generally to 4.2(H) 

 feet, but sometimes to 5,300 feet. Noted in Upper Nisqually Valley ; Upper Klickitat 

 River, at 4.200 feet ; mouth of Hellroaring Canyon, at ."..sou (eel : aboul Mount Adams 

 and Eagle Mountain; on Goose Prairie along Bumping River, at 3,520 feet J on Dewey 

 Lake (head of American River), at 5, .'100 feet. In Olympic Mountains from sea level 

 to lower slopes. Locally noted at Tacoma, Port Ludlow, Lake Cushman, on shores of 

 Puget Sound, and about Dryad, at 304 feet elevation. In Colvillc National Forest, 

 Blue Mountains (Wenache National Forest), at 2,500 to 5,000 feet. 



Oregon. — Stream bottoms and lower slopes of Cascade and coast ranges. Blue and 

 Powder River mountains. In northern Cascade National Forest, on ltoth sides of 

 and generally up to 1,100 feet; lower slopes of Mount Hood. Farther south (R. 5 to 17 

 S.) it reaches 200 to 6,000 feet. In southern Cascades National Forest, extending south- 

 ward, on west slopes of Cascades, to headwaters of Umpqua. River, and on east slopes 

 to Mount Jefferson. Exact southern limit imperfectly known. In Coast Range south 

 ward into California. Locally noted in vicinity of Portland ; coast of Clatsop County ; 

 from lower Clackamas River bottoms to point about 6 miles above " Hot Springs " in this 

 canyon ; Blue Mountains, at 2,500 to 6,000 feet. 



California. — In fog belt of northern coast, extending inland 10 to 30 miles, and 

 southward to north of Fort Ross (Sonoma County). Locally noted in Del Norte County 

 at Crescent City, and in bottoms of Smith River. Humboldt County: Inland to Hoopa 

 Valley and ridge east of Hoopa Valley, at 3, Too to 5,500 feet : lower Mad River ; 

 Eureka; from Ilydesville inland nearly to Bridgeville and Little Van Dusen River (10 

 miles east of Bridgeville i ; Ferndale to Bear Valley; between Capetown and Petrolia 

 and thence to Upper Mattole. Mendocino County: Along coast from Kenny to West- 

 port and inland along Laytonville road to point 15 miles from Westport ; gulches close 

 to coast from Fort Bragg to Gualala : Mendocino inland, on road to Ukiah, nearly to 

 Orris Hot Springs; Navarro River up to a point 12 miles from mouth: Elk Creek, near 

 Greenwood (12 miles south of Navarro Riven. Sonoma County: Coast north of Fort 

 Ross with Pinua murioata. 



The detailed range of this fir in Idaho, Montana, and Wyoming will be 

 described in a later bulletin. 



OCCURRENCE. 



A tree of moist situations. On alluvial stream bottoms and their border valleys, lower 

 gentle mountain slopes, depressions, and gulches. Best and most abundant growth in 

 coast region on stream bottoms at low levels; small at high elevations. Its deep root 

 system demands fairly deep, preferably moist, porous, well-drained soils. With favorable 

 moisture and climatic conditions, it grows well on rather poor, thin soils, but better 

 quality is necessary in soils deficient in moisture and subject to rapid evaporation. 



Rarely in pure stands ; usually in mixture. Most commonly with Douglas fir, and 

 dominant over western red cedar, western hemlock. Pacific yew. and vine maple. At low 

 levels in Oregon and Washington, with latter trees and sparingly also with amabilis and 

 noble firs, broadleaf maple, red and Sitka alders, and black cottonwood ; in low coast 

 region with Sitka spruce, and in California with redwood. 



Climatic CONDITIONS. — Climate of range favorable to tree growth. Summers com- 

 paratively cool and humid: winters ordinarily mild, and changes of temperature rather 

 gradual: in Bitterrool Mountains ( Idaho i and northward, temperature falls occasionally 

 to —30* F. Precipitation, well distributed, except in July and August, which are usually 

 rainless over greater part of range. Forest floor is then dry, and destructive fires often 

 occur. Annual precipitation, from less than 20 inches to over 100 inches in different 

 pans of range. 



Tolerance. — For a fir only moderately tolerant of shade, being less so than amabilis 

 fir, western red cedar, western hemlock, and California yew, but more tolerant than 

 noble til-. Douglas fir, western white pine, western larch, and yellow pine. Seedlings 

 endure considerable shade, but in later life full overhead light is needed tor best growth. 

 Young growth under ordinary shade remains dwarfed and dies within a few years, unless 

 overhead lii;ht is admitted. Willi overhead light, but shaded from side, height growth is 

 rapid, trunks are readily cleared of branches, and long, clean stems are formed. Shade 

 endurance varies in general with age, moisture of soil and air, exposure, quality and 

 quantity of soil, altitude, and latitude. With sufficient moisture, soil, and heat this fir 

 thrives in full sunlight, and also endures considerable shade. On poor, dry soils in 

 warm exposed places, shelter and some shade are beneficial to reduce soil evaporation 



