168 THE AURIFEROUS GRAVELS OF THE SIERRA NEVADA. 
Garber’s, which is only a few hundred feet distant up the cafion. If there ever was a deep chan- 
nel from Red Dog to Waloupa, there must have been subsequent important changes of level, unless 
some such explanation as the one which will be proposed farther on (page 172) be adopted ; for, 
as tne rock now lies, the water must have run up hill at some part of its course. That the rock at 
Red Dog is not exceptionally low (as might possibly be supposed) is clear from the fact that the 
exposures at Independence and Bunker hills are only a few feet higher, — enough, barely, to give 
an easy grade from the north. The discussion of the question of probable change of level I will 
not enter upon ; for it will lead too far, and involve too many considerations with which I am only 
imperfectly acquainted. As far as our observations extended, however, the weight of evidence 
seems to be against any theory of great change of level; and for the present it will be assumed 
that the position of the slate-rock is essentially what it was at the time of the deposition of the 
gravel. 
On this supposition it seems more natural that the course of the — or a — deep channel was 
from Cozzens and Garber’s towards Red Dog. At a later day, no doubt, the whole of the region 
between Red Dog and You Bet was covered with water, and channels may have been cut in a 
great many directions. Having met this difficulty in our attempt to trace the course of the old 
channel, two questions arise: first, if the stream which flowed to the southwest from You Bet 
is not a continuation of the Red Dog channel, where did it come from? and, second, if a channel 
flowed from Cozzens and Garber’s to Red Dog, where was its outlet, and what was its source ? 
It may be thought possible that the lowest points at Cozzens and Garber’s and at Mallory’s have 
not yet been reached, and that there is still a chance for a nearly level bed-rock all the way from 
Red Dog to Niece and West’s. Such a supposition is, to be sure, possible, but I can see no in- 
dependent evidence in its favor. 
In attempting to find the continuation of the You Bet channel at some other point than at Red 
Dog, attention is naturally turned first to the east and northeast, tu see if there is any chance for 
the channel’s having come down either under or to one side of the present Sugar Loaf and Chalk 
Bluffs. A careful exploration was made of the whole extent of gravel from Chicken Point to 
Boston Hill, which led to the conclusion that the main channel could not have come through this 
way. The observations on which this conclusion was based were substantially as follows. 
At the extreme southern end of Chicken Point the gravel reaches out on a narrow spur for 
about a quarter of a mile beyond the main body. The banks are not very high, and there was 
never any great depth to bed-rock. I took no special observation at this part of the mines, hut 
the altitude of the hill at the end of the gravel will not be far from 3,050 feet. A spot near the 
middle of the Chicken Point mines, where bed-rock was to be seen, was pointed out to us from 
the bank by Mr. Heydliff. When I went to the spot, I first saw the rock in a pit twenty-five or 
thirty feet across and twenty-five feet deep, through which a tunnel had been run as an outlet for 
a claim higher up. The bed-rock had been cut into about fifteen feet. Following up the line of 
this tunnel in a direction about N. 10° E. (magnetic), the bed-rock was seen to rise regularly for 
a distance of two or three hundred feet. Farther east I saw no bed-rock in the Chicken Point 
mines; but the sandy strata dipped to the north and east, as if the rock might possibly slope off in 
that direction again, — though of this there can be no certainty. The altitude of the highest point 
of rock seen I determined to be 3,066 feet. 
Previously to this I had taken an observation with the barometer on the iieieoe at the head of 
Sardine Ravine, at a point 350 feet south of the high flume. Its altitude I made 2,907 feet. It 
dipped to the north, — that is, under the gravel, —and shortly disappeared from sight ; but, not- 
withstanding, the dip of the strata of clay and sand near by was mainly to the south and south- 
west. The gravel in this neighhorhood contained considerable sand and clay, — some black and 
indurated, and some more yellowish in color. The presence of large and rather angular boulders 
was also noticeable. 
These were the only two places on Chicken Point south of the ridge of gravel along which the 
Chalk Bluffs road runs, where the altitude of bed-rock could be measured, though there was plenty 
