8 THE AURIFEROUS GRAVELS OF THE SIERRA NEVADA. 
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 
range 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, chiefly 
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 
parallel main branches, which run in corresponding longitudinal depressions, 
heading opposite the very highest part of the range, on the south flanks of 
