of
the placer gold production. Hydraulic mines in Chaffee and Park
counties produced the greater part of the remainder, but there was an
increased yield from Routt County, and a dredge also made an output in
Costilla County. In metallurgical treatment nearly 60 per cent of the
total tonnage of Colorado in 1910 was sent to amalgamating, cyaniding,
or chlorinating mills, and the remainder was smelted, with or without
previous concentration. Of the Cripple Creek tonnage 95 per cent was
treated at local cyanide plants at Cripple Creek and at cyanide,
chlorination, and concentrating plants at Colorado City.
The
silver production of Colorado in 1910 was 8,509,598 fine ounces,
against 8,902,633 ounces in 1909. Lake County (Leadville), which made
an increase in output of over 500,000 ounces in 1909, showed a decrease
of 101,627 ounces for 1910, but the output was 39 per cent of the State
yield in 1910, against 38 per cent in 1909. There was notably increased
silver output in Chaffee, La Plata, and Ouray counties, but the Pitkin
County production again decreased, and there was a considerable
decrease also in San Miguel County. Smaller decreases were recorded in
all the other counties except Clear Creek, Gunnison, Park, Saguache,
and Summit. The production of the leading counties in 1910 was as
follows: Lake, 3,322,015 fine ounces; San Miguel, 1,144,050 ounces; San
Juan, 782,250 ounces; Mineral, 773,722 ounces; Pitkin, 477,813 ounces;
Clear Creek, 475,174 ounces; and Ouray, 414,250 ounces. These 7
counties combined furnished nearly 87 per cent of the total. The
districts of Leadville, Aspen, and Creede combined, producing mainly
smelting ores, made an output of 4,409,274 ounces, against 4,657,884
ounces in 1909. The San Juan region produced 2,625,033 ounces in 1910,
against 2,737,239 ounces in 1909. Siliceous or dry ores yielded
6,117,719 ounces of silver .in Colorado in 1910, or 71.9 per cent of
the total output; lead ores yielded 1,050,611 ounces, or 12.3 per cent;
zinc and lead-zinc ores, 711,810 ounces, or 8.4 per cent; copper ores,
436,358 ounces, or 5.1 per cent; and copper-lead ores 188,146 ounces,
or 2.2 per cent. The quantity of silver recovered from placer gold was
nominal.
Idaho.—The
gold production of Idaho in 1910 was $1,096,842, a decrease of
$356,980, due largely to the closing of the Buster mine, in Idaho
County, and the Trade Dollar mine, in Owyhee County, and to decreased
output from other mines in Custer and Lemhi counties. Siliceous ore
furnished about 71 per cent of the output, mainly from Owyhee, Elmore,
and Boise counties, and placers $242,546, or 22 per cent. In order of
production Owyhee County led with $388,728, followed by Boise with
$199,430, and Elmore with $180,282. No other county produced $100,000
in gold in 1910. The Boise Basin region, in Boise County, produced
$168,051 in gold in 1910, of which $127,954 was from 42 placers,
including dredges, and the remainder from 7 deep mines, against
$175,852 from 9 deep mines and 39 placers in 1909. The Middle Boise
district, in Elmore County, produced $127,818 in gold in 1910, mainly
from gold-milling ore. The Bagdad-Chase mine, the largest producer, was
closed in March, 1910, but the mill was run on tailings. The Elk City
district, in Idaho County, produced only $37,533 in gold in 1910
against $174,036 in 1909, the decrease being largely due to the
idleness of the Buster mine. The Carson district, in Owyhee County,
produced $388,268 in gold in 1910 against $424,237 in 1909, the
decrease being due in large part to the
