SAN JUAN TO NORTH BLOOMFIELD. 393 
Perkins, or Mr. Hamilton Smith, make it 525 feet below the same point. ‘These discrepancies 
could be in part reconciled on the assumption that my measurements make Grizzly Hill higher 
than it is in reality, but any change in the value I obtained for the altitude of that point would 
lead to other difficulties, for my determinations of the altitudes of Grizzly Hill and of Gopher Hill, 
on the opposite side of the South Yuba, agree almost exactly with what is known, by means of 
observations with the hand-level, of their relative positions. It is true there may be some error in 
regard to Gopher Hill, for I had only a very short series of observations with the mercurial 
barometer at Sailor Flat to depend upon, but it is impossible to tell where the error lies. Be 
these things as they may, however, the essential fact of the slight difference of level between the 
points under consideration remains unaffected, and we can only say that similar discrepancies may 
be expected when the barometer is employed to determine slight differences of level, unless an 
extended series of synchronous observations can be obtained. Badger Hill, as may be seen 
on the map, overlooks the cation of the Middle Yuba, and Grizzly Hill is in a corresponding 
position on the opposite side of the ridge, but higher up, overlooking the South Yuba. Between 
them, and superficially connected with both, lies the immense deposit of gravel at Columbia Hill 
(or North Columbia, if the official name of the post-office is preferred). The only possible course 
for a tributary to the old stream from the neighborhood of Grizzly Hill is along the line now 
followed by Spring Creek (or Knapp Creek, both names being in use), for there are hiils of bed- 
rock to the east and the west sufficiently high to prevent its going in any different direction. The 
junction of the main stream and the tributary, then, must have been at some point near the present 
site of Columbia Hill; certaimly it could not have been much farther down the stream. The 
average grade of the oid channel between Badger Hill and Malakoff has already been stated to be 
seventy-two feet to the mile, a grade which is in good accord with those ascertained for portions 
of the channel lower down the stream. From this it is clear that at the point of supposed junction, 
allowing the grade to be uniform between the extreme points, the bed-rock in the main stream 
would be considerably higher than that in the tributary at a point a mile and a half away. To 
make such a junction possible, the bed of the old stream must have been very steep for the first 
two or three miles below Malakoff, and then very nearly flat for the remainder of the distance to 
Badger Hill. In the absence of any facts that can be cited in support of this view, I am inclined 
to the belief that no deep channel will ever be found with a grade descending to the north or north- 
west from Grizzly Hill. 
It is fair to say here that a generally accepted view among the mining men of this region is that 
such a deep channel does exist, and there may be reasons for the correctness of this view with 
which I am not acquainted. The balance of testimony, however, seems to me to incline in the 
other direction. A vast accumulation of tailings in Spring Creek has covered the original bed 
of the creek to a great depth, and there is now no easy method of telling just where the old rim- 
rock appeared on the surface of the ground. Slate bed-rock is now to be seen in the bed of the 
creek at the bridge on the road from Columbia Hill to Grizzly Hill, at an altitude certainly higher, 
though, to be sure, not much higher, than at the outlet of Grizzly Hill. The bed-rock continues 
in sight for a considerable distance up the creek on the right, or west, bank. On the left, or east, 
bank, gravel is seen immediately after crossing the bridge, and it forms a border to the tailings in 
the creek on that side, which grows gradually narrower as the high slate hills to the north approach 
nearer to the creek. At one point on the east bank of the creek, about half a mile above the bridge, 
I saw bed-rock at the present level of the tailings, and, of course, considerably higher than the 
bed-rock at Grizzly Hill. These projecting masses of slate narrow very much the limits between 
which any deep channel from the direction of Grizzly Hill can have come, and I was told that bed- 
rock was struck within thirty feet of the surface at all points where prospecting was carried on in the 
bed of Spring Creek in the earlier days of mining, before the tailings from the hydraulic banks had 
been deposited. Doubtless the gravel was continuous across some of the upper portions of Spring 
Creek, near the line between the Columbia Hill property and that next above, between Columbia 
Hill and Lake City, and in all probability the deep channel will there be found and some day worked. 
