CHEROKEE FLAT: BUTTE COUNTY. 207 
depth of the portion yet left to be washed at seventy yards, the total amount 
of gravel still available for hydraulic mining purposes will be, in round num- 
bers, 700,000,000 cubic yards. Estimating seven cubic yards as the amount 
of gravel that may be washed by a 24-hour inch of water, on ordinary grades, 
and knowing the total possible delivery of water by the three companies 
owning the ditches by which this region is supplied, which delivery may be 
stated, in round numbers, at 4,000,000 inches annually, it follows, according 
to Mr Hague, that the whole length of fourteen miles of channel, if opened 
and rendered available for mining, may be washed in from twenty-five to 
thirty years. 
§ 2. Cherokee Flat, and the Region near Oroville. 
Low down on the foot-hills, about on the same elevation as the Smartsville 
gravel, there is in Butte County, between Oroville and Dogtown, an import- 
ant placer and hydraulic mining region which properly comes up at this 
place for description. Unfortunately the data in possession of the writer in 
regard to this district at the present time are exceedingly meagre. The 
geological features of the vicinity of Oroville and Pence’s Ranch, ten miles 
farther north, near Cherokee, have been described with some fulness in the 
“ Geology of California” ; but the hydraulic mining operations, which have 
only rather recently assumed great importance, were never examined by the 
Geological Survey with any detail. The general character of the region is 
similar to that of the other districts farther south already described. There 
is, namely, a volcanic capping overlying heavy beds of sandy material, with 
gravel at the bottom, and the latter is rich in gold. 
The Table Mountain of Butte County, which extends from Oroville to 
Cherokee, a distance of about eight miles, resembles in many respects the 
Table Mountain of Tuolumne, being like that capped with basaltic lava, and 
forming a very conspicuous feature of the topography of the region. The 
quantity of gravel which underlies the Oroville basaltic table is, however, as it 
appears, much larger than that under the Sonora flow. There are numerous 
isolated table-capped elevations north of the main mass, which is itself cut 
into and eroded away at various points, especially at Cherokee and Morris's 
Ravine, exposing large areas of gravel. It is said that the channel extends 
as far north as Dogtown, a distance of fully twenty miles. This north and 
south direction of the channel corresponds with that of the present drainage, 
the North Fork of Feather River running almost exactly parallel with this 
