THE MINERALS OF IDAHO 59 



less, and King veins at the headwaters of Elk Creek, the Wilson group 

 a little farther north and other veins between Summit Flat and 

 Kempner yield free gold with some sulphides in quartz veins. A 

 specimen of oxidized ore from the Overlook mine contains spongy 

 and mossy pale colored gold in cavities from the removal of sulphides 

 in leached and rusty quartz. Placers occur along Lost River and 

 Bear River near Kempner. 



In the Westview (Willow Creek, Pearl, Rock Creek) district 

 placers were worked in the early days, and the Red Warrior mine 

 was located in 1870. This district contains a great number of veins 

 which are fault fissures in granite on either side of which the rock is 

 altered by sericitization and impregnated with pyrite. Along the 

 fissures occur narrow seams of auriferous sulphides— pyrite, black, 

 or dark brown coarse grained sphalerite, arsenopyrite, and galena 

 which are rich in gold. The sparse gangue consists of quartz and 

 calcite. No visible gold can be seen even on panning the richest 

 sulphides. The surface ore is soft and limonitic and contains free 

 gold associated with some cerusite. 



BONNER COUNTY 



In the Mooyie Yaak district the Buckhorn mines east of Mooyie 

 River and 10 miles north of Kootenai River have produced ore con- 

 taining native gold associated with galena. 



CASSIA COUNTY 



The Snake River placers have made a small annual production 

 of fine gold for many years. 



CLEARWATER COUNTY 



In the Burnt Creek district productive gold placers around Dent 

 are worked by hydraulicking and sluicing. 



In the Musselshell Creek (Wieppe) district placer gold has fo r 

 years been mined from gravels along Lolo Creek. The deposits 

 are not of extraordinary richness. The gold is fine in size but is 

 relatively low grade, being worth only $15 to $17 an ounce. 



The Pierce district was the first important placer district discovered 

 in the State. The placers were never remarkably rich but produced 

 well in 1861-62. The production in 1874 was $70,000. There has 

 been desultory placer and quartz mining ever since. The placer 

 production as given for 1908 was $41,255 and for 1909 with 11 mines 

 operating $43,390. Much of the recent work has been done by 

 dredges. The gold averages 0.820 fine (82 per cent Au). 



CUSTER COUNTY 



In the Loon Creek district the gold ores consist of auriferous chal- 

 copyritc in a quartz-sideritc gangue, the principal deposit being the 

 Lost Packer mine. Such ore contains 2 to 3 ounces of gold to the ton. 



