436 SUPPLEMENTARY INVESTIGATIONS IN THE GRAVEL REGION. 
The town of Alleghany lies on the opposite side of Kanaka Creek, and at a little higher altitude 
than Chips’s Flat. The bed of the creek at the trail-crossing is over six hundred feet below the 
level of the town. ‘The outlet of the channel from Forest City is at Smith Flat. There was a 
little hydraulic mining done at first, which was soon followed by drifting. Drifts or tunnels were 
driven many years ago through the ridge between Alleghany and Forest City, and the mines are 
now practically abandoned. — I made no attempts to enter the old mines either at Alleghany or at 
Chips’s. The pay-gravel is reported to have seldom exceeded three feet in thickness. 
Forest City is built near the junction of the north and south forks of Oregon Creek, at the base 
of Bald Mountain. It owed its earlier prosperity to the rich drift mines under the Alleghany 
ridge ; its present importance is a natural result of the successful mining operations, which have 
been conducted under the lava to the north and northeast of the town. There has never been 
an opportunity for much hydraulic mining. There used to be a large number of mining claims 
worked in this vicinity, to which it will not be necessary to refer in detail. At present the most 
extensive and profitable mine is that of the Bald Mountain Company. The North Fork Company, 
owning the adjoining ground to the west, has driven a long prospecting tunnel, and is still engaged 
in the prosecution of the work. By the kindness of the superintendents, Mr. H. Wallis of the 
Bald Mountain and Mr. Platt Ketchum of the North Fork Company, I was allowed to spend half 
a day in each of these two mines. The mining operations at Forest City have been described in 
considerable detail in Raymond’s Report for the year 1874, pp. 151-155, and in that for 1875, 
p. 103. Extracts from these descriptions have been already given,* and my present report is in 
part supplementary to what is there stated. 
The Bald Mountain mine is worked through a tunnel, which, though not straight, has a general 
northeasterly direction, and is now about a mile in length.t The mouth of the tunnel is in 
gravel, about twenty feet above the bed-rock. At a distance of 300 feet from the mouth a spur of 
serpentine bed-rock was struck, through which the tunnel had to be driven for 400 feet. Beyond 
the serpentine the tunnel for the rest of its length is entirely in gravel, or partly in gravel and 
partly in bed-rock, with the exception of 225 feet, where the old channel has been cut away by a 
peculiar flow of lava, or voleanic mud. The grade of the tunnel near its mouth is four feet to the 
hundred, or 211 feet to the mile; but farther in the grade is reduced, and at the extreme end it 
is only two feet to the hundred. Eighteen hundred feet from the mouth of the tunnel there is a 
shaft which was sunk from the surface. The first forty feet of the sinking was in the mountain- 
cement; then came two hundred and fifteen feet of irregularly stratified pipe-clay and sand, 
beneath which there were fourteen feet of gravel. The drifts and breasts are laid out both to the 
east and the west of the main tunnel, and are carried until rising bed-rock is met or the pay-gravel 
of the bottom is exhausted. The average width of the deep channel is about 500 feet. I tried to 
find out the width of the old channel at Alleghany and Chips’s Flat, but with no good success. 
The estimates given me varied between 400 and 2,000 feet. The gravel is exclusively white 
quartz. Upon the bed-rock there are some small quartz boulders, but seldom more than two feet 
in diameter. There are occasional streaks of sand in the gravel, but no pipe-clay so far as I saw, 
either in the tunnel or in the drifts. Petrified wood is found, but no animal fossils. The drifts 
and breasts are about three and a half feet high on the average, including from a foot to a foot and 
a half of bed-rock. The softness and clayey character of the rock causes the gold to settle below 
the gravel, and the upper bed-rock is perhaps as rich as the lower gravel. The character of the 
bed-rock, it is asserted, has a remarkable effect upon the richness of the gravel. Where the rock 
is serpentine, the gravel is poor or barren; where it is a black slate, the yield is a maximum. The 
white slate is also a favorable rock, but not quite so favorable as the black. At Chips’s Flat I was 
told that on the blue lead the white slate was the best rock for catching gold. There is such 
an unanimity of opinion in regard to the favorable or unfavorable character of certain varieties of 
* See ante, pp. 213, 214, 
+ The plan (Plate S, Fig. 1), copied from a map made by Mr. Wallis, and kept at the office of the company, 
shows only a part of the mine. The results of the more recent surveys have not yet been put upon the map. 
