placers
in Arizona, Nevada, and New Mexico, by V. C. Heikes, were published in
the Survey report on gold and silver for 1912, copies of which may
still be had on application to the Director, United States Geological
Survey, Washington, D. C.
DREDGING.
The
production of gold by dredging in the United States from the commercial
beginning of the industry in 1S96 to the end of 1919 has amounted in
value, according to best available data, to $153,342,048, of which
$110,342,831 came from California, $20,394,894 from Alaska, $9,109,528
from Montana, $5,815,943 from Colorado, and $4,096,118 from Idaho.
Oregon produced more gold from dredging in 1916,
1917,
1918, and 1919 than Montana or Idaho and nearly as much as Colorado,
and the total production from dredges in Oregon has been about
$3,196,000.
Brief
details of dredging operations have been given in Mineral Resources in
the mines reports on gold, silver, copper, lead, and zinc in the
Western States and also in earlier reports of the Director of the Mint.
A brief history of gold dredging in the United States was given in the
general report on gold and silver for the year 1914, and the production
of gold obtained by dredging in the United States and the number of
dredges operated were given by States for each year from 1896 to the
end of 1914. Further information is to be found in reports of
geological surveys or mining officials of different States. A
comprehensive and very useful report is contained in Bulletin 57 of the
California State Mining Bureau. Other valuable treatises are "Dredging
for gold in California," by D'Arcy Weatherbe, published by the Mining
and Scientific Press, and Bulletins 121 and 127 of the Bureau of Mines.
The gold recovered in the United States by 91 gold dredges in 1919 was $10,346,216, against $10,342,100 by 93 dredges in 1918. The increase in 1919 was $4,116, following a decrease of $2,208,325 in
1918.
Of the output in 1919, California produced $7,716,919 from 46
dredges, Alaska $1,360,000 from 28 dredges, Montana $265,590 from 3
dredges, Colorado $542,103 from 6 dredges, Idaho $164,854 from 5
dredges, and Oregon $296,750 from 3 dredges. No dredges were operated
in 1919 in Nevada, Wyoming, South Dakota, or the Appalachian States,
but a dredge was under construction in Nevada, and it was operated in
1920. There was also an output of $217,455 in gold from dredges
operated in the Philippine Islands in 1919, but this is not included in
the table given on page 694.
