total recovery of gold by dredging for the period 1903-1921 is $23,107,452.
No important new placer-bearing areas were reported in 1921.
Silver.—The
mine production of silver in Alaska in 1921 was 761,085 fine ounces,
against 953,546 ounces in 1920. The copper mines produced 545,229
ounces, a decrease of 136,804 ounces; the siliceous ores 99,515 ounces,
against 246,292 ounces in 1920; and the placers 22,565 ounces, against
25,221 ounces. Lead ores yielded 93,776 ounces in 1921.
ARIZONA.
Gold.—The
mine production of gold in Arizona in 1921 was $2,930,-303, or
$1,855,819 less than in 1920. Placers contributed only $12,524. The
deep mines produced $2,917,779, of which 83 per cent came from -dry and
siliceous ores mined chiefly in Mohave, Yavapai, and Cochise counties,
and 15 per cent was contained in copper ores mined chiefly in Cochise
and Yavapai counties. Mohave County had a gold output of $2,333,506,
Cochise County of $381,841, and Yavapai County of $112,984. The gold
recovered from ores treated at gold and silver mills represented about
80 per cent of the total output, against 60 per cent in 1920, and crude
ores shipped to smelters contained about 16 per cent. The crude copper
ores mined and smelted directly (without previous concentration!
contained an average gold content of about 63 cents a ton.
Silver.—The
mine production of silver in Arizona decreased from 5,355,303 fine
ounces in 1920 to 2,469,394 ounces in 1921. Of this output 1,241,436
ounces came from copper ores, 580,349 ounces from dry and siliceous
ores, 645,563 ounces from lead ores, and 1,956 ounces from copper-lead
ores. Cochise County produced 1,467,145 ounces in 1921, of which
651,301 ounces came from copper ores and 360,918 ounces from siliceous
ores; and Yavapai County produced 383,193 ounces, derived mainly from
copper ores. Bullion recovered from gold and silver ores, almost all by
cyanidation, contained 134,726 ounces of silver, concentrates 320,573
ounces, and crude ore shipped to smelters 1,971,116 ounces.
CALIFORNIA.
Gold.—In
1921 the deep mines produced $7,549,998 (an increase of $299,568), of
which gold-quartz ores yielded 99.1 per cent. California placers in
1921 produced $8,"154,824 in gold, or $1,094,211 more than in 1920. Of
the placer production $7,756,787 was recovered by dredging. The total
dredge production from 1896 to the end of 1921 has been $124,999,984,
and the production by dredges in 1921 was equal to 49 per cent of the
total gold for 1921.. The Yuba County dredges, 10 in number, made the
largest output, the value being $4,722,564, an increase of $1,266,112.
Sacramento County, with 7 dredges working, made an output of
$1,687,646, an increase of $112,902. In Butte County (including
Oroville and other districts) 4 dredges produced $420,017 in gold, or
$21,633 less than in 1920. Dredges were also operated in Calaveras,
Amador, Stanislaus, Placer, Shasta, and Trinity counties.
Five of the 31 counties reporting mine production of gold each had a yield of more than $1,000,000 in 1921. Of these Yuba and
