GOLD MmiNG m COLORADO. 539 



Average assay value in coin — gold, $131 21; silver, $16 22 — total.. $147 43 



Total tons raised 863. 27 



Average assay value, coin $28 92 



Average yield, per ton, of milling ore, in currency 12 68 



Average yield, per ton, of smelting ore, in currency 110 07 



Average yield, per ton, of all ore, in currency 14 17 



Average cost, per ton, for ordinary expenses of mining and milling, 13 59 



Average cost, per ton, for special expenses 2 03 



Total average cost, per ton, in currency 15 67 



Counting gold at 20 per cent, premium, the average percentage obtained 

 of the value of the low-grade ore was 39 per cent, by milling, and 62 per cent, 

 of the value of first-class ore, obtained by sale to the smelters. 



On the same slope of Quartz Hill with the Burroughs, but from half a 

 mile to a mile further west of the principal developments on that lode, and 

 higher up the valley, is another group of mines opened upon ledges that from 

 their course, dip, and relative position seem to belong to the same class as the 

 Burroughs, Gardner, Illinois, and their associated veins, but which present a 

 marked difference in the character of their ores; carrying a much larger pro- 

 portion of argentiferous galena, zincblende and sulphurets of silver. Assays 

 of the ore frequently show a very high value in the last named metal. Prom- 

 inent among these are the California, Indiana or Hidden Treasure, Flack, 

 Mercer County, Forks, American Flag, and others. The Mercer County lies 

 east of and in line with the Flack, on what is understood to be the same vein, 

 but the mines are separated by a dry, shallow ravine, which crosses their 

 course. The California and the Indiana bear a similar relation to each other, 

 the two names applying to different parts of one vein, the last named lying 

 west of the ravine, just referred to, and the California lying east of it. The 

 course of the California, continued still further east, shows it to be very nearly 

 in line and probably identical with the Gardner lode, already described. The 

 Forks is between the Flack and the California, having, apparently, a course 

 considerably north of east, and, consequently, intersecting both, if all three are 

 continuous and regular. It is worked actively to a depth of over 300 feet, and 



