RANGE OF THE GRAVEL REGION. 



55 



Gabriel Range, and in some of the valleys of the San Bernardino Mountain 

 are, or have been, worked for gold at various times during the winter season. 

 They arc not the scene of extensive and permanent mining operations, like 

 those hereafter to be described ; but rather of the nature of the ordinary 

 placer-mining gravels; that is, of local origin and comparatively unimportant. 









The deep canons of the rivers of the extreme northern counties — especially 

 the Klamath and its branches — contain large amounts of gravel, which have 

 been, at times, quite extensively worked for gold, and in places with large 

 profits. This region has never been systematically explored by the Geo- 

 logical Survey, but there is no reason to suppose that these gravels differ 

 from ordinary river deposits of detrital origin, except in being on a scale of 

 magnitude corresponding with the depth of the canons. They have not 

 been, up to the present time, so far as known to the writer, the object of 

 systematic and permanent mining operations, such as those carried on in the 

 gravel-mining region proper, and they will, therefore, not be included among 

 the topics discussed in the present volume. Yet it will be readily admitted 

 that both these more northern as well as the southern gravels demand a 

 careful examination, especially with a view to forming some better idea than 

 we now possess of their probable future importance. 



The gravel region proper, or that portion of the western slope of the Sierra 

 Nevada here to be especially described, may be said to be nearly conter- 

 minous with the belt of auriferous slates, the range of which has already 

 been indicated in the preceding chapter. In the region where granitic 

 rocks prevail, whether in the southern portion of the Sierra, or along the 

 crest of the range, the gravels are local in character, and are not washed for 

 gold. This statement, however, needs some explanation and limitation, and 

 this will be found a little farther on, when describing the nature and range 

 of ordinary placer-mining operations. The gravel-mining region proper may 

 therefore be said to begin in Mariposa County and to extend into Plumas, 

 as far as the line already indicated as marking the limit beyond which the 

 slope of the Sierra is entirely covered with volcanic material. But all por- 

 tions of the area thus designated are by no means equally important cither 

 in respect to the amount or the richness of the gravel which they contain. 

 Mentioning the counties in their geographical order from north to south, we 

 find the importance of the gravel deposits increasing as we go from Tuo- 

 lumne to Calaveras, and thence to Amador. El Dorado, Placer, Nevada, and 

 Sierra are the great mining counties, and there is a gradual falling off in 





