Silver in quartz or siliceous ores increased mainly from the output in West View district, Boise County, and Carson, Flint, and French districts, Owyhee County. kSilver from ores cyanided decreased in quantity in Ow}'hee and Custer counties.
Lead ores increased the silver yield in the Coeur d'Alene region of Shoshone County, in Spring Mountain and Texas districts of Lemhi County; also in Lava Creek, Mineral Hill, and Warm Springs districts of Blaine County and in Bayhorse district of Custer County.
The increased output of copper ores has caused the yield of silver to be increased in Shoshone and Custer counties.
The reports returned from mine operators in Idaho numbered 1,063. Of this number, 619 lode mines and 84 placers reported development and assessment work. The remainder, 360, were producing properties. One hundred and twelve of these were quartz or lode mines and 248 were placer mines. In addition, 107 reduction works at mines, 15 dredges, and 2 smelters were reported.
Of the 107 reduction works connected with mines, 63 mills (including 3 arrastras), 8 dredges, and 2 copper smelters were in operation; 44 mills (including 5 arrastras) and 7 dredges were idle. Of the 50 operating quartz mills, 32 used stamps for crushing the ores. Eighteen used crushers and rolls of various patterns. Twelve of the 50 operating mills used direct amalgamation with batteries and plates, 16 used amalgamation followed by concentration, and 5 used amalgamation followed by treating the tailings with cyanide. Thirteen were concentrating plants, and 2 used direct treatment of the crushed ores by cyanide.
ORES SOLD OE TREATED.
Mine operators in Idaho reported on cards prepared for the purpose the total number of ounces or pounds of metal, including gold, silver, lead, copper, and zinc, produced for the calendar year. When the report was thus made, the average commercial price was used in obtaining the value. When values only were given, if consistent, they were allowed to remain. The total tonnage of ore smelted and milled, of concentrates produced, and of old tailings treated by cyanide, with the total values of each summed up, are as follows:
Tonnage and value of ore treated in Idaho in 1904[Short tons.]