442 SUPPLEMENTARY INVESTIGATIONS IN THE GRAVEL REGION. 
mile from the mouth of the creek granite boulders were again met, which evidently came from 
the granite country at the head of the creek. 
The altitude of the cabin at the Blue Gravel claim is 5,938 feet. The cabin stands upon the 
voleanic capping, near its lower limit. The capping at this point is composed mostly of boulders, 
some of which are of undoubted volcanic origin. Many of them are light-colored crystalline rocks, 
which at first sight have a striking resemblance to quartz. They generally show a partially 
rounded exterior. From the cabin I climbed about 500 feet up the slope of the ridge, and esti- 
mated that the crest was still between six and seven hundred feet higher. The surface was covered 
with boulders, similar to those seen lower down, in connection with boulders of granite, which were 
abundant. One persistent stratum, locally known as “ pipe-clay,” though having only a distant 
resemblance to the pipe-clay of the gravel mines, is seen cropping out in all the ravines. It is 
really a sandy streak, carrying much crystalline matter, brilliantly white when seen from a little 
distance, and reminding one in its general appearance of the Chalk Bluff at You Bet. Had I had 
more time, I would have climbed to the crest of the ridge. I wanted to inspect more closely what 
appeared to be castle-like masses of black and solid lava, extending as a broken and rugged ridge 
along the highest crest. Seen from below, this mass, which, judging from the appearance of a few 
scattered boulders, I suppose to be very different in character from the main body of the capping, 
appeared to be at least fifty feet in thickness. 
There is a very general belief prevalent in the mining community of Sierra County that under 
these accumulations of boulders, sandy strata, and other voleanie material (if, indeed, it be strictly 
voleanic, and not in part glacial), there are old auriferous gravel channels much broader and more 
extensive than those existing at lower altitudes. Mr. Hendel appears to have adopted this view in 
the report prepared for Mr. Raymond, from which extracts have been given in a previous chapter.* 
It is thought by some that a channel will be traced from Haskell’s Peak by way of Chips’s Hill 
to a junction with another channel coming from a more easterly direction, and that the two united 
follow a course under the lava, by way of American Hill and Nebraska, to some point near Forest 
City, where a union is effected with the Bald Mountain channel. Others think that the high 
channel followed an independent course towards the south, and crossed the line of the present 
Middle Yuba River near the site of Milton, without making any connection at all with the lower 
channel, which passes by Forest City. 
It was the reports of recent discoveries of gold and of extensive prospecting in this vicinity that 
made me decide to visit the region, and to get what information I could in regard to this question 
of the existence of high channels and in regard to actual mining operations. The partial exami- 
nation that I was able to make in-the short time at my disposal, at an unfavorable season of the 
year, is hardly sufficient to justify the expression of any decided opinion; but I may be allowed 
to say that I failed to see any very strong evidence upon which to rest a belief in the former ex- 
istence of large rivers. I am not ready to assert that there are no old gravel channels in this part 
of the Sierra Nevada: I do not think it proved that there are any. The mining operations are 
still on too small a scale to settle the question. 
I have already alluded to the Pliocene shaft and other exploratory works on the ridge near 
Forest City. In their unfinished condition these works show that persons can be found with con- 
fidence enough in the existence of a channel under the lava to spend money in hunting for it, but 
do not prove anything further. Undertakings similar in character have also been begun at higher 
points. The Savage Company, of which J. T. Mooney of Sierra City is the superintendent, has 
been engaged since the summer of 1877 in sinking a shaft and driving a tunnel at a claim on the 
southern slope of the ridge, about half-way between Forest City and Sierra City. The shaft 
has reached a depth of 139 feet. The present length of the tunnel is something over 325 feet. 
Owing to the lateness of the season, I was obliged to 2bandon my proposed visit to this claim. 
At the Blue Gravel claim, east of Milton Creek, a small amount of work has been done, but all 
* See ante, pp. 210, 211. 
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