840 MINERAL RESOURCES, 1914----PART I.
County
(including Oroville and the outside districts) decreased in output
$485,411. Altogether the dredge production of California fell off in
1914 to the amount of $306,900, due mainly to exhaustion of certain
fields.
The
counties leading in output of gold in 1914 were Nevada, with
$3,301,948; Amador, with $3,082,002; Yuba, with $2,800,713;
Sacramento, with $2,164,491; Butte, with $1,697,120; Calaveras, with
$1,336,875; and Shasta, with $1,101,202. Of these Yuba, Sacramento,
and Butte are mainly dredging fields; Amador and Calaveras are on the
Mother Lode; Shasta produces from both siliceous and copper ores; and
Nevada produces mainly from gold-quartz milling ores of the Grass
Valley district.
The
five Mother Lode counties—Amador, Calaveras, Eldorado, Mariposa, and
Tuolumne—whose output is also mainly gold milling ores, produced
$3,235,116 in gold from mill bullion and $1,809,682 from concentrates
in 1914, or $5,044,798 in all, against a total output of $4,678,053 in
1913.
Silver.—Mine
production of silver in California was 1,471,859 fine ounces in 1914,
against 1,378,399 ounces in 1913. Nearly half of the output, or 703,042
ounces, came from copper ores, chiefly from Shasta County, but also
from Calaveras County, and 448,054 ounces came from silver-lead ores,
mainly from Inyo County. Smelting oie produced altogether 1,267,752
ounces. The remainder came from milling ores, principally by
amalgamation and cyanidation.
COLORADO.
Gold.—The
mine production of gold in Colorado in 1914 was valued at $19,883,105,
against $18,146,916 in 1913—an increase of $1,736,189.
The
Cripple Creek district produced $11,996,116, or 60 per cent of the
State output, an increase of $1,091,113 over the output of 1913. The
Roosevelt Tunnel continued to lower the water level in the mines
drained by it, and an important extension of the tunnel is now being
driven to drain the country including the Vindicator and Golden Cycle
mines, an additional distance of over 10,000 feet, along the line of
tunnel. Flow of water has considerably increased and a much greater
increase is expected when the extension leaves the granite and enters
the breccia. In this last-named ground the services of the tunnel as a
means for prospecting at depth are also expected to increase in value.
The completed work will drain the ground below various shaft collars at
the following depths: El Paso, 1,289 feet; Vindicator, 2,100 feet;
Golden Cycle, 1.955 feet; Blue Bird, 2,300 feet; Portland, 2,145 feet;
Elkton, 1,645 feet; Findley, 2,295 feet; Last Dollar, 2,175 feet;
Cresson, 1,925 feet; American Eagles, 2,645 feet.
The
San Juan region, in Dolores, La Plata, Ouray, San Juan, and San Miguel
counties, produced $3,969,857, a decrease following a decrease in 1913.
There was, however, an increased output of $252,616 in Ouray County.
Besides this county and Cripple Creek (Teller County) increased output
was shown in Summit, Park, Lake (Leadville), Gunnison, Clear Creek,
Chaffee, and Boulder counties, but there was notable decrease in
Gilpin, Mineral, Custer, and Hinsdale counties.
