THE CANONS OF THE RIVERS. 65 
rock, as the section is intended to exhibit the position of the surface of the 
slates on which the more recent detrital materials have been accumulated. 
An examination of the table of altitudes given in the Appendix to this work 
will also illustrate the statements here made as to the great elevation of the 
surface between the streams above their present beds. As we go north from 
the South Yuba, the depth of the cafions increase. The difference of level 
between the Middle Fork of the Feather at Nelson’s Point and the summit 
of the adjacent lava-capped mass of Pilot Peak is fully 5,650 feet. The ele- 
vation of Mount Clermont, on top of which is a mass of gravel covered by 
lava, is 3,570 feet above the valley at its base; that of Spanish Peak, also 
capped with gravel and lava, nearly 3,800 feet above American Valley. An 
excellent idea of the topography of the hydraulic mining region is got by 
the traveller passing over the line of the Central Pacific railroad, in descend- 
ing the slope of the Sierra. After passing Blue Cajion, the slates begin to 
be met with, and all along below this, especially in the neighborhood of 
Dutch Flat, and beyond that for several miles, the road passes through a 
region of hydraulic mines, keeping on what seems to be a broad plateau, 
which has an elevation of a little over 3,000 feet above the sea-level. Sud- 
denly, just before reaching Colfax, a sharp bend in the line, at a place called 
Cape Horn, brings the road bed just on to the edge of the caiion of the North 
Fork of the American, down into and along which there is an unobstructed 
view for eight or ten miles, the bottom of the cafon being about 1,600 feet 
below the level of the road. The effect of the scene presented to the eye 
from this point is extremely striking, because the spectator has not been pre- 
pared, by anything which he has previously seen, to expect to find the flanks 
of the Sierra so deeply cut into by the streams, which seem of insignificant 
size as compared with the immense troughs at the bottoms of which they 
run. 
In view of what has been stated in reference to the great elevation of the 
divides between the streams in the mining region of the Sierra, it will be 
easily understood how the miners, beginning their operations in the lower 
portion of the range, at first almost exclusively limited themselves to the 
river beds and their immediate vicinity. Gradually, however, they extended 
the range of their “prospecting” on to the areas between the rivers, and 
followed them up until they found themselves at a much higher elevation, 
and working under very different conditions from those who kept to the 
“river diggings.” With the gravels found in these higher localities the miners 
