80 FOREST TREES OF THE PACIFIC SLOPE. 



of high wind-swept crests, from 3 to 5 inches in diameter, are from 150 to 200 

 years old. Extremely large trees occasionally found would doubtless prove to 

 be from 500 to 600 years old. 



RANGE. 



Yukon Territory and British Columbia to southern Oregon and through the Rockies 

 into New Mexico and Arizona. Rocky Mountains of western Canada from Peace River 

 southward through western Montana and Idaho, western Wyoming, eastern Nevada, 

 Utah, western Colorado, New Mexico, and Arizona ; westward to east slope of Cascades 

 in Washington and to west slope in Oregon, extending southward to California border. 

 In Canada, at elevations from 2,500 to 6,000 feet ; at 4,000 to 6,000 feet in Washington ; 

 at 8,500 to 11,000 feet in Arizona, and at 8,500 to 12,500 feet in Colorado. 



Western Canada (Yukon Territory, British Columbia, Alberta). — East slopes of 

 Rockies in Yukon Territory westward throughout British Columbia south of Peace River 

 plateau (lat. 55° 45') ; probably only to inland slope of Coast Range, and not in more 

 arid parts of southern interior plateau nor on mountains above 6,000 feet. Northern part 

 of British Columbia, on streams at 2,500 to 3,500 feet, reaching Babine and McLeods 

 lakes ; northern limits not yet determined. Eastern limit at south is Cascade Mountain 

 on Bow River (along Canadian Pacific Railroad). Locally noted at Laggan, Kicking Horse 

 Lake, Rundle Mountain (near Banff), Lake Louise, Kamloops Valley (central British 

 Columbia). 



Washington. — East slope of Cascades and northeastern mountains ; generally at 4,000 

 to 6,000 feet elevation. Washington National Forest appears to be mainly on east side, 

 at 4.000 to 6,000 feet ; in sheltered passes occasionally up to 6,800 feet and down to 

 2,100 feet, as in Stehekin River valley, where it. extends westward from an island about 

 5 miles above Lake Chelan to within 15 miles above Lake in lower edge of Abies amabilis 

 growth. Other eastern limits are White River canyon (nearly to reserve line), Stamilt 

 Creek (branch Columbia River south of Wenache River, long. 120° 20'), and divide 

 between Yakima and Columbia rivers (Kittitas County), at 4,500 to 5,200 feet. Reported 

 also on west side of Cascades on headwaters of Skykomish, Snoqualmie, Cedar, and 

 White rivers. Mount Rainier National Forest, at 1,000 to 6,200 feet elevation ; Mount 

 Rainier, at about 3,500 feet. Locally noted as follows : Mount Adams ; Early Winter 

 Creek ; Bridge Creek, at 4,250 feet ; Stillaquamish River below Silverton ; Chelan-Entiat 

 Divide, at 0,400 feet ; peak southeast of Twisp Pass ; tributary Similkameen River near 

 Windy Pass, at 6,125 feet ; Rattlesnake Creek ; head of North Fork of Entiat River, at 

 7,000 feet ; Emerald Basin, south of Lake Chelan, at 5,500 feet ; peaks south of Rainy 

 Pass ; Slate Creek ; Falls Creek ; Crater Pass, at 6,000 feet ; Goat Mountain, at 4,800 

 feet ; Upper Klickitat River, at 4,200 feet. Colville National Forest, in basins and 

 draws, above 4,000 feet elevation. 



Oregon. — Cascades southward to California line ; also in Blue and Powder River 

 mountains ; in north, generally at 3,000 to 5,500 feet, but at 5,500 to 8,000 feet, in south. 

 In northern Cascades, mainly in groups on east side of range in canyons and on high 

 cool slopes ; similarly scattered also on west side of range, on streams down to 2,500 feet. 

 Locally noted on Mount Hood, at 3,000 to 6,000 feet, and at Badger's Lake and Brooks 

 Meadow, Wasco County. In southern Cascades, grouped or scattered on both sides of 

 main divide in canyons and on damp slopes, at 5,600 to 8,000 feet ; limited, on east side, 

 to few larger canyons and moister slopes, but sometimes, as in high country between 

 Mount Pitt and Klamath Point, forming 75 per cenf of stand in canyon bottoms — upper 

 canyon of South Fork of Rogue River (T 34 S., R. 5 E). Not on Umpqua-Rogue Divide, 

 nor in Klamath Pass, but reported on Siskiyous (Ashland National Forest) at head- 

 waters of Ashland Creek (T. 40 N., R. 1 E) ; reported also from north end of Coast 

 Range, near Astoria, at 3,000 to 6,000 feet. Blue Mountains, wide ridges and at heads of 

 streams, above 3,000 feet ; John Day River ; also in Powder River Mountains (north- 

 eastern Oregon). 



OCCURRENCE. 



Tree essentially of high altitudes ; its presence controlled to great extent by supply of 

 soil moisture, demands for which limit its occurrence to high elevations or to land moist 

 from springs, seepage, or overflow. Lower range limited to moist canyons or to pro- 

 tected north slopes, while on other exposures it finds suitable soil moisture only at 

 higher altitudes. Owing to lower temperatures and less intense light at north, favorable 

 moisture conditions occur there at lower elevations than in south ; hence the gradual 

 lowering of altitudinal range from 8,500 to 12,000 (south) to 6,000 feet (north), with 

 increasing latitude. This variation is not consistent throughout the range, but is often 

 influenced by local climatic factors. Of merchantable size at middle and lower levels ; 

 stunted or depressed at timber line. Shows little preference of soil, if sufficiently moist. 



