190 THE AURIFEROUS GRAVELS OF THE SIERRA NEVADA. 
unexpectedly found the rock pitching the other way, and on that inclined surface the gold 
appeared in surprisingly large quantities. On the other side of the ridge — Shelby (or Selby) 
Flat —the prospecters worked up in the same way until they found the rock pitching away from 
them, and then stopped. The Coyote Diggings were said to have been the richest diggings in this 
immediate neighborhood, and it is a pity that no accurate record of the amount taken out was 
kept. Not knowing the yield per year nor the amount of bank washed away per year, of course I 
can make no estimate as to the amount of gold found in each cubic yard of gravel. 
The petrified and charred trunks of trees which have been found in the Manzanita channel may 
just be noticed. Some of them have been as much as five or six feet in diameter, — sometimes so 
much petrified on the inside as to require blasting to remove them, while the outside is easily 
broken and cut away. I could not hear of any instance where the position of the tree-trunks 
would serve as a key to the course of the channel. 
There are several isolated patches of gravel, sometimes covered by a volcanic 
capping, and sometimes uncovered, to the west of Nevada City, along on the 
divide between Deer Creek and the South Yuba. The first of these is Connor — 
Hill, which is on the divide between Rush and Deer creeks and about four 
miles west of Nevada City. There is a considerable amount of gravel, made 
up of rounded quartz pebbles, on the northern end of this hill. It had not, 
however, been attacked, in 1870, on account of the difficulty of getting 
water to so high and isolated a locality. According to the single baromet- 
rical observation taken at this point, the top of Connor Hill is several feet 
higher than the office of the South Yuba Water Company, at Nevada City. 
Where this gravel came from, or what the direction followed here by the 
channel, is, at present, only a matter of conjecture. To the east and north- 
east is the valley of Rush Creek, and it is possible that the original channel 
of this hill was once as high as the present top of Connor Hill. That it 
could have crossed from Cement Hill seems, according to Professor Pettee, 
hardly probable. To the northwest and west lies Illinois Ravine, once the 
scene of rich shallow placer diggings. This ravine heads near Newtown, 
and follows a nearly north course to its junction with Rush Creek, where it 
contracts to a narrow gorge. The gold of this ravine had evidently the 
same origin as that on Connor Hill. 
In attempting to solve the question of the probable continuation of the 
lava flow of Cement Hill, the valley of Rush Creek was examined in consid- 
erable detail. No indications were observed of a probable passage of the 
channel in that direction. 
At the Empire Shaft, which was sunk at the western end of Cement Hill, 
the thickness of the detrital formation is about 140 feet ; of this seventy-five 
feet was lava cement, then a stratum of pipe-clay, and under it gravel. From 
a poimt not far from the bottom of the shaft, the bed-rock, which here is 
