8 



THE AUKIFEEOUS GEAVELS OF THE SIERRA NEVADA, 



r 



the plateau. As one consequence of this condition, we have in the Sierra a 

 chain with — so to speak — only one slope ; at least the western slope of the 

 rano-e is of vastly more importance in every way than the eastern ; indeed, 

 the limits of the latter, from the head of Owen's River north, cannot be so 

 easily defined. The geological and topographical conditions indicated in the 

 preceding pages, and to be more fully enlarged on in those which follow, 

 are well illustrated by the distribution of the population of the State of 



■ 



California. This is almost entirely concentrated in two groups : one, agri- 

 cultural and commercial, about the Bay of San Francisco and in the valleys 

 which connect with this great break in the Coast Ranges ; the other, chietly 

 mining, on the west slope of the Sierra Nevada, and very much concentrated 

 in the region between Mariposa and Plumas counties, or the very section 

 over which the auriferous gravels occur which form the subject of the 



present volume. 



In a rapid review of the most important topographical features of the 



Sierra Nevada, we naturally begin with the highest division, or that lying 

 between the parallels of 36" and 37° 30'. In this portion of the range, the 

 eastern slope is well defined and very narrow — it being hardly more than 

 ten miles in width — and exceedingly steep. The descent, on the average, 

 is over 1,000 feet per mile in that part of the Sierra which is opposite Owen's 

 Lake. The western slope, on the other hand, is here about fifty miles in 

 width, and has an average slope of about 250 feet to the mile. On the 

 eastern border of the Southern High Sierra there is the well-marked depres- 

 sion occupied by Owen's Lake and the river of the same name, with the steep, 

 lofty, and narrow chain to the east of this, known as the Inyo and White 

 Mountain Range. All of these topographical features — the crest of the 

 Sierra, Owen's Valley, and the Inyo Range — are nearly parallel with each 

 other, and have about the same direction as the main axis of the Sierra 

 Nevada, namely, N. 31° W. The elevation of the main crest of the Southern 

 Sierra is from 12,000 to 13,000 feet, with numerous points exceeding 14,000, 

 but no one — so far as known — quite reaching 15,000 feet. 



The drainage of this elevated region is chiefly effected by Kern, King's, and 







the San Joaquin rivers; the first and last named of these run for long distances 

 in secondary depressions parallel with the axis of the range, and then turn and 

 break through at right angles to their former direction. The Kern has two 



O O O 



parallel main branches, which run in corresponding longitudinal depressions, 

 heading opposite the very highest part of the range, on the south flanks of 



