Page 99 - miningincalif1927

gravels of the middle fork of the american river. 91

South Side of Forest Hill.

Mines on the south side of Forest Hill drain into the Middle Ameri-

can River.
Baltimore and Dardanelles. At the Dardanelles there is a bank of

gravel left because the reservoir was above it. To the east of this the
Baltimore has a point on which there is estimated to be at least 2,000,-
000 cubic yards. The Dardanelles formerly yielded 13 cents per cubic
yard.* This gravel is cemented but would wash readily at a duty of
2 after blasting. 48,600 M. I. D. were used in 1880. Much more

would be available if the ditches were cleared.
The Paragon Mine at Bath (also called the Breece and Wheeler)

could easily be fitted for work and has two ditches. The Tod's Valley
or Pond ditch with 600 miner's inches from Volcano Canon and the
Breece and Wheeler Ditch with 1500 miner's inches from El Dorado
Canon; 113,500 M. I. D. from these streams were used on this side of
Forest Hill in 1880. No water has been taken for other purposes on

this ridge, and more water would be available as the mines on the
north side of Forest Hill would not be using it, but the ditches would

need clearing. From 1.874 to 1879 this mine was worked by hydraulic
method only and produced $243,075.87 from which dividends were
paid amounting to $119,670.14. This yield of gold equalled $2.54 per

miner's inch of water used, a high return (see Ex. Doc. No. 98, p.
24). The IX Report of the California State Mineralogist records that

a bank of gravel 70 feet high gave 74.2 cents per cubic yard 124,000
yards yielding $92,000.00. Another bank 71 feet high gave 78 cents
per cubic yard, 22,275 yards yielding $17,387.78.
When hydraulic work was stopped, this mine was drifted at the
bottom or Blue Lead and also on a richer pay streak called the Para-
gon 160 feet above bedrock and a third streak called the Orono ; from

these it gave regular returns.
As a result of this drifting, future hydraulic results would be lower.
The bottom gravel contains many large boulders, some being granite.
The ordinary gravel contains pebbles stained green with chlorite,
which the miners say is a very favorable indication for gold.
Above the gravel there is a cover of tuffs and then andesite. This

would reduce the returns, but the andesite has been eroded so that the
amount of cover would not increase much for 100 yards of work

behind the present bank. Gravel miners consider this mine is rich,
but the barren cover must be moved. When drifting had been car-
ried on for 3850 feet, a barren channel filled with volcanic material

was encountered (Whitney p. 94). Drifting was done over a width
of 200 to 300 feet and the trough was stated to be 4000 feet wide.
About 15,000,000 cubic yards could be worked without trouble
from the andesite cover. The yield is difficult to forecast. In many
districts the old miners piped away the overburden and lighter top
gravel and got rid of it as fast as possible. Having done this they
prepared to pipe the "gravel" and if they estimated the quantity of
gravel piped or the returns from a bank it was usually "pay gravel'

that they considered. Top stuff was only cover or surface material,

*Ex. Doc. No. 98, p. 23.