VIEWS CONCERNING TERM COAST RANGES. 76 



pressed seem to him to have been more completely substantiated by the 

 results of field-work since their i)ublication. 



Great misconceptions have existed in regard to the real geologic condi- 

 tions existing in the Coast ranges, both as to their age as well as to their 

 relation to the supposed older range, the Sierra Nevada, and it is hoped 

 that some light can be thrown on these questions. 



The Term Coast Ranges. 

 different geologists' conception of the term. 



Tlie designation Coast ranges as applied to that series of mountains 

 bordering the coast of California is a very indefinite one and, owing to 

 the topographic features, one which it is difficult to make exact. The 

 term was first used by Fremont''^ in 1843. Tlie names current among 

 the Si)aniards Avere those of individual ranges or peaks. 



Dr Trask, in the opening of his first report,'!' si)eaks of the Coast ranges 

 as extending from the forty-second parallel (northern boundary of the 

 state) to the Mexican line. Later he proposed to divide the coast moun- 

 tains south of San Francisco bay into Coast ranges proper, lying to the 

 west of the Santa Clara and Salinas valleys, and the Monte Diablo range 

 bordering the San Joaquin valley. In another place he says it is pro- 

 posed by Blake to ai)ply the term Peninsula range to all those mountains 

 south of the thirty-fifth parallel north latitude to distinguish them from 

 the Coast mountains, as well as the Sierra Nevada. In his second report if 

 he emi)hasizes his belief that the Coast ranges should be considered as 

 terminating in southern San Luis Obispo county, and that the Santa 

 Ynez range, rising from the sea at point Arguello and extending in a 

 direction more nearly east and west, belongs pro])erly to the San Ber- 

 nardino sierra. 



J. S. Newberry, § one of the geologists of the Pacific Railroad Survey, 

 ex})resses the following view : 



"As far north of San Francisco as cape Mendocino the Coast monntains have the 

 same general northwe.'-t trend, and a more plausible supposition than that the Cas- 

 cades form a continuation of the Coast mountains would ])e that the latter ranj^'es 

 terminate at cape ^Fendocino, and that the Coast mountains of Oregon were a con 

 tinuation of the Sierra Nevada. It is not necessary to suppose this, liowever, but 

 it is sufficient to ctjnsider tlie Coast mountains of Ore,ij;onas the Coast mountains of 

 California, defiecte<l from the trend which they preserve ])elow cape Mendocino, 

 and that the ranges of the coast and of the interior inosculate on either side of the 

 forty-Hec»nd i)arallel in the Calapooya, Umpqua and Siskiyou mountains." 



•Exploring Expedition to Oregon imd California, 1843. 

 t State Senate Documents, no. !», IS'yi. 

 tStato Senate Dociinnents, no. 14, Ik.jC. 

 gl'acific Railroad Survey, vol. vi. p. 2'J. 



