FOREST TREES OF THE PACIFIC SLOPE. 



315 



account of its very porous, brittle structure. In some sections of its range 

 the tree is important and much used for fuel. Its rather frequent occurrence 

 in continuous patches renders it worthy of attention for this purpose. 



Longevity. — Age limits are not fully known. Probably moderately long- 

 lived. Trees from 16 to 25 inches in diameter are from 170 to 275 years old. 

 It is doubtful if this oak attains a greater age than 350 years, and it probably 

 reaches maturity in about 175 years. 



Fig. 140. — Qucrcus californica. 



Central Oregon, in mountains, southward through California, in coast ranges and 

 west slope of Sierras, nearly to Mexican boundary. On mountain slopes, low summits, 



elevated valleys and canyons, but not on plains nor near sea; in north, usually at 

 1,500 to 3.000 feet elevation, and in soutli. at 4,000 to 7;000 feet. 



Oregon. — Very abundant in valleys of central and southern part, west of Cascades, 

 from McKenzie River (lat. 44° 15') southward; on mountain slopes considerably above 

 2,000 feet, entering lower part of yellow pine belt, and being especially frequent on 



