6 GEOLOGY OF THE EUEEKA DISTRICT. 



less than eight times, and again on June 10 and 11 In summer the days 

 are warm, and for the most part cloudless; the nights cool. The daily 

 variation between the maximum and minimum thermometers was always 

 very considerable, frequently showing a difference of 40 F. For the three 

 summer months of June, July, and August, of 1880, the maximum ther- 

 mometer in the shade stood over 90 F. on eighteen days, or one day in 

 six. As the climate is very dry, the heat was seldom oppressive, except 

 in some inclosed basin or valley. As early as August 30, the thermometer 

 fell below the freezing point, and on October 9 a light fall of snow covered 

 both mountain and valley. 



History. In the summer of 1864 the first locations of mining property 

 were made in New York Canyon, on the easteni side of Prospect Mountain, 

 near the present " 76 " Mine. This property was known as the Eureka 

 Mine, and although it never fulfilled the expectations of its original owners, 

 it transferred its name to the very successful property on Ruby Hill and 

 subsequently gave a name to the town, to the mining district, to the county, 

 and finally to the neighboring group of mountains. The original property 

 gave so little promise that the district was finally abandoned. In mining 

 operations very little was accomplished until the spring of 1869, when im- 

 portant discoveries were made on Ruby Hill and active, intelligent work 

 was undertaken. The Champion and Buckeye claims on the south side of 

 Ruby Hill were the first properties located, and soon afterward the ground 

 was broken on the now famous Richmond and Tip Top Mines. From that 

 time forward mining operations on Ruby Hill have gone on steadily, and 

 to-day the Eureka District is the most successful mining region in the state 

 of Nevada. Success on Ruby Hill was quickly followed by active enter- 

 prise developing mining locations on both slopes of the ridge of Prospect 

 Mountain, in Secret Canyon, and in the Silverado Hills in the southwest 

 corner of the district. 



Estimates of the value of the ore production of the district since the 

 first shipment of crude bullion in 1869 are as follows : 



From 1869 to 1873 $10,000,000 



From 1873 to January, 1883 50,000,000 



Total 60,000,000 



