in
1910 were in Yuba, where there was an increase of $734,408, due mainly
to dredging; in Amador, where there was an increase of $347,461, mainly
from quartz mining on the Mother Lode, and in Sierra, where there was a
net increase of $122,363, entirely from quartz mining, as placer
production decreased in this county in 1910. The largest decreases were
$499,288 in Butte County, mainly in dredging; $310,077 in Tuolumne
Count}-, in quartz mining on the Mother Lode; $292,806 in Calaveras
County, mainly in mining on the Mother Lode, but also from placers;
$272,940 in Sacramento County from dredging; and $126,752 in Nevada
County, where placer production fell off over one-half, although
production from quartz mining in the Grass Valley region increased in
1910. The counties producing over $1,000,000 in gold in 1910 were Yuba,
with $3,204,273; Amador, with $2,646,246; Nevada, with $2,533,483;
Butte, with $2,487,791; Shasta, with $1,533,728; Sacramento, with
$1,396,874; and Calaveras, with $1,147,705. Of these Yuba, Butte, and
Sacramento counties are essentially producers from dredging; Amador
and Calaveras are Mother Lode counties; Nevada County production is
mainly from the gold-quartz ores of Grass Valley; and Shasta County
produces gold in important quantities mainly from siliceous and from
copper ores. Butte County, which ranked first in total
f
old production in
California in 1909, dropped to fourth in 1910; fevada County, which
ranked second, dropped to third; Yuba County, which ranked third, rose
to first; and Amador County, which ranked fourth, rose to second. The
changes were mainly due to increased recovery by dredges in Yuba County
and decreased output from this source in Butte County, to increased
quartz-gold output in Amador County, and to decreased production from
drift mining and surface sluicing in Nevada County. The five Mother
Lode counties— Amador, Calaveras, Eldorado, Mariposa, and
Tuolumne—whose ores are mostly gold quartz, produced altogether in gold
$4,408,990 in 1910, as against $4,821,416 in 1909. Of these, Amador
County alone increased production in 1910, the others showing
decreases. The total average recovery in gold and silver from Mother
Lode ores in 1910 was valued at $3.78 per ton, against $3.60 in 1909,
$3.72 in 1908, and $4.66 in 1907. The total output of gold from
dredging in California continued increasing in importance in 1910,
when the production from this source was $7,550,254—the largest in the
history of the industry. The increase is to be credited mainly to Yuba
County, however, and in smaller degree to Siskiyou and Trinity
counties, for the other great dredging counties, Butte and Sacramento,
decreased their output, owing to decreasing tenor of the gravels
worked. The total production of gold from dredging in California from
1899, when the output was $206,302, to 1910, inclusive, has been
$40,318,775. The rate of increase rose rapidly every year until 1906,
but since 1908 the rate has steadily declined. Placer gold production
from all sources in California in 1910 was valued at $8,888,795,
against $9,104,433 in 1909. Of the total for 1910 $635,498 came from
168 hydraulic mines, $7,550,254 from 72 dredges operated by 41
companies, $516,929 from 139 drift mines, and $186,114 from 185
sluicing mines; in 1909, $605,608 came from 134 hydraulic mines,
$7,382,950 from 63 dredges, $739,797 from 118 drift mines, and $376,078
from 241 sluicing mines. The total gold production from California deep
mines in 1910 was $10,826,645, against $11,133,437
