618 MINING INDUSTET. 



enterprises are in progress. The hill, known as Glacier Mountain, which 

 forms the divide between the South Snake and Bear Creek, has been pretty 

 thoroughly prospected, and a large number of lodes have been opened. Many 

 of these have produced experimental lots of rich ore, and a few have been 

 already developed to such an extent as to prove their value and to invite the 

 investment of a good deal of capital for the equipment of the mining works 

 and the provision of metallurgical facilities. 



CoMSTOCK. — The best developed and, thus far, most important mine in 

 this neighborhood is that of the Boston Silver Mining Association, opened on 

 the Comstock lode, under the superintendence of Mr. John Collom. This lode 

 is on the west slope of Glacier Mountain, and about 1,000 feet above the bed 

 of the creek at its base. It was discovered in 1865, but a very little work 

 was done upon it during that or the following year. In 1867 more active 

 operations were undertaken; thelode was partially developed, a saw-mill and 

 dwelling houses were erected, and some experimental appliances provided 

 for working the ores. Since that time its development has proceeded grad- 

 ually, having been interrupted during the winter seasons, owing to the severity 

 of the climate and the difficulty of communication with the sources of sup- 

 plies, materials, and labor. 



Fig. 5, on Plate XXXV, presents a longitudinal section of the mine, 

 showing the extent of its workings in August, 1869. It has been opened 

 entirely by the means of tunnels, to which method the exceedingly steep 

 slope of the hill is admirably adapted. The upper level, reached by a cross- 

 cut tunnel over 100 feet long, is from 60 to 100 feet below the surface, and 

 300 feet in length on the vein; the lower level, reached by a tunnel 150 feet 

 long, is opened for a distance of 250 feet on the vein, and is 70 feet below 

 the upper level. Some stoping has been done, as indicated in the drawing. 

 From these developments it appears that the course of the lode is about 

 north 15° east, true; its dip is practically vertical, though sometimes inclin- 

 ing a little to the east or west. Its width varies from one to eight feet or 

 more, averaging three feet. Its course is regular, the walls are well defined, 

 and the filling of the vein is remarkably uniform in character. The country- 

 rock is of mixed granitic and gneissic character. The main filling of the 

 fissure, which is usually separated from the walls by a seam of clay, or 



