CHAPTER III. 



THE IDAHO BASIN. 



GEOGRAPHICAL POSITION. 



The Idaho Basin includes the headwaters of Moore Creek, a tribu- 

 tary of the Boise River, and is located at a distance of 25 miles in a 

 northwesterly direction from the city of Boise, at about latitude 

 43 50' and longitude 115 50'. In comparision to its size this dis- 

 trict has produced a very large amount of gold, chiefly from placer 

 mines, but also considerable from quartz mines. The area embraced 

 in the Idaho Basin that is to say, the productive part of the same 

 does not exceed 150 square miles. Its length from north to south is 

 15 miles and its maximum width about 13 miles. 



DISCOVERY AND HISTORY. 



The placer mines of the Idaho Basin were discovered in August, 

 1862, by a party of prospectors from Walla Walla. During the fall 

 of the same year the party is said to have been attacked by Indians, 

 and its leader, Grimes, killed at Grimes Pass. The party, after 

 ascertaining the richness of the placer deposits, returned to Walla 

 Walla and formed a new expedition of 52 men ; this party reached 

 the basin the same year. The prospectors located first at the pres- 

 ent site of Pioneerville. Subsequently the gold gravels of Centerville 

 were located, and in December of the same year the rich diggings at 

 Idaho City and on Granite Creek were found. Rapidly following 

 these discoveries came explorations of other mineral-bearing parts of 

 Idaho. In 1863 Rocky Bar and the rich mines of Owyhee were found. 

 The influx of miners was extremely rapid after the report of the first 

 discoveries had spread, and one year after the discovery several thou- 

 sand placer miners were operating in the region. From 1862 to the 

 present date placer mining has been carried on continuously, the 

 operation being limited only by the amount of water available. Nat- 

 urally, however, the output has gradually decreased since the first 

 years following the discovery, when, as usual in placer regions, the 

 maximum production was reached. 



At an early date quartz mines began to be exploited, as it was soon 

 seen that the placer deposits led up to the decomposed croppings of 

 numerous quartz veins. At that time, however, quartz mining was 

 in its infancy, and the ores could not always bear the cost of the treat- 

 ment, increased in this case by the long distance over which machinery 

 had to be transported and the high wages demanded for labor. At 

 the present time there is a considerable quantity of gravel still left 

 for exploitation, but these deposits will in time be exhausted, and the 

 gold production will then have to depend on the quartz mines. In 

 1867 and 1868 at least ten mills are reported to have been in operation. 



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