170 THE AURIFEROUS GRAVELS OF THE SIERRA NEVADA. 
eight feet in the course of 150 feet and then to pitch off suddenly to the northeast. And for the 
next three or four hundred feet no bed-rock has been found, because, there being no chance for a 
cheap drainage into Missouri Caion, there has been no attempt made to reach bottom by shaft 
sinking. On the farther side of the mine the bed-rock rises almost precipitously, so that its highest 
point (near the northeastern bank of the mine) has an altitude, as estimated by the hand-level with 
reference to known objects, of fully 3,040 feet. In the central part of the mine, according to Mr. 
Hussey, “ blue gravel” was uncovered in digging to connect with the sluices and boxes at the out- 
let. A section across this part of the gravel is given on Plate F (Fig. 5), — the vertical as well as 
the horizontal scale being two hundred feet to the inch. Beyond this high rock Mr, Hussey thinks 
there is still another channel, with a southerly or southeasterly course, but of this I was not 
fully convinced. There is, however, in the next small excavation to the north, a comb of bed-rock, 
dipping both to the east and west and apparently a continuation of the high rock in Hussey’s 
Mine. To the east of this comb the bed-rock has not yet been struck, which circumstance adds, 
it is true, some weight to the theory of the additional channel. Still, there may be no real con- 
nection between the two exposed masses of rock, or the latter may be nothing more than a high 
place, like an island in the stream. 
Keeping along in nearly the same direction, the next point of bed-rock measured, beyond Hus- 
sey’s, was in the bottom of the mines on Darling’s Hill, near the western bank. Its altitude we 
determined to be 3,064 feet. Other rock was seen at about the same elevation at a number of 
points on Darling’s and Boston hills, but it was by no means clear that there was any dip to the 
east. The general slope of the country from Darling’s Hill is to the west, and considerable slate 
is seen between the mines on the hill and those at Red Dog, as is seen by following the line of 
the Bunker Hill ditch from near the outlet of Hussey’s Mine. For one or two hundred feet from 
Hussey’s slate-rock is seen; but it soon disappears, and the ditch is dug in gravel for nearly a 
quarter of a mile. At the westerly end of the hill, about a quarter of a mile east of the town of 
Red Dog, slate-rock was met again in the bottom of the ditch, and its altitude determined to be 
2,908 feet, — almost identical with that at the head of Hussey’s sluices. From this point on (with 
the exception of perhaps a hundred feet of gravel near by) the ditch runs entirely in slate around 
the north side of Darling’s Hill and the head of Arkansas Cafion, to where the water is taken 
down to the Bunker Hill Mine. 
The altitude of the bed-rock at Red Dog has been already given as 2,621 feet. The same result 
was also obtained for the bed-rock at Independence Hill on the opposite side of Arkansas Cafion 
from Red Dog. The rock not being very even at either place, an error of two or three feet could 
easily be made in fixing upon the point to be measured, so that these two results are to be re- 
garded not so much as deciding anything about the direction of the channel between the two 
places, as corroborating the general statement that there is a fall of about thirty feet from the 
bottom of the Cozzens and Garber shaft to the bed-rock at Red Dog. 
The highest point of the Independence Hill gravel is nearly 200 feet above the bed-rock, being 
about on a level with a small gravelly knoll, at the east end of the high flume, the altitude of 
which was determined to be 2,821 feet. On the northern side of Independence Hill I also deter- 
mined the altitude of a point on the rim — at the outlet of a small claim discharging into Green- 
horn — to be 2,723. feet. 
The observation at the bed-rock of Williams’ mine on Bunker Hill — by which the altitude was 
made to be 2,632 feet — was taken at a later date than the others, when the nearest station barom- 
eter was at Colfax, and is consequently not to be trusted quite so implicitly as the others in the 
series, though there is no probability of any great errors. Both at Independence and Bunker hills 
the gravel shows the same succession of blue and red as is seen at Red Dog and below You Bet. 
These are the principal points where observations for altitude of bed-rock were taken within the 
You Bet and Red Dog districts. For convenience of comparison, the results, so far as they shed 
light upon the question of direction of channel, may be brought together as follows :— 
