1818 REPORT OF THE CHIEF OF ENGINEERS. 



Prospecting for the gold-bearing quartz in the mountains above, whence the placers 

 derived their value, was not neglected ; the result was the discovery of the expected 

 veins, and in addition thereto valuable lodes of silver. From the specimens there- 

 from valuable assays in Silverton and Denver, it was said, resulted. They are, how- 

 ever, of a refractory nature, resemble, in certain respects, some ores of the Uncom- 

 pahgre district, and do not yield to the simplest forms of silver reduction. There ex- 

 ists, moreover, it was said, a suspicion of deposits containing tellurium traces, the 

 North Star lode possessing, as we were informed, such constituents. The telluride 

 ores, as is well known, are all of remarkable richness. 



Such are the prospects ; the reality, the present, unless changed since last Septem- 

 ber, is heavily obscured. Prospectors are something like sheep — they are very gre- 

 garious. All that were seen or were met were leaving the section, and spoke despond- 

 ingly of its prospects. The buildings of the town, it may be remarked, are of an 

 unusually fine character for a small mining camp, and it is said to have possessed at 

 one time a summer population of 400 to 500 ; in September last business, however, was 

 dead and was departing to its younger and more prosperous rival, Animas City. No 

 reduction-works or stamp-mills of any kind were found at the town. This is to be 

 regretted, and is but an illustration of the fact that mismanagement or other causes 

 blighting the prospects of a promising camp will deter capital thereafter for entering 

 for a short time, at least, if not for a long period. 



Abundantly and not far distant are found the necessary formations for fluxing, 

 while valuable deposits of coal exist upon the La Plata, as they do in sections to its 

 east. 



THE DOLORES DISTRICT. 



Prospectors from Parrott City and other points have turned their attention to the 

 slopes at the headwaters of the forks of this river, and a number of lodes have been 

 located, resulting in the organization of subdistricts or small camps lying in La Plata 

 County and in Ouray. The ores are chiefly the carbonates, the mineral being chiefly 

 low grade. Specimens from the district, brought away as part of our general collec- 

 tion, include carbonates containing from 63 to 70 per cent, of lead, and from 136 to 

 216 ounces of silver, zinc blende and galena, argentiferous galenas of a very low grade, 

 and one with gray copper traces. The district has not advanced beyond the early pri- 

 mary or simple prospecting state, and no excitement was apparent in regard to the 

 prospective fortunes to be realized. 



THE SIERRA LA SAL. 



This mountain group, as is well known, owes its name to the large saline deposits 

 there existing. Prospecting for the precious metal has been prosecuted there at inter- 

 vals, and it is reported not without success. Whatever indications have been ob- 

 served, however, have been at the risk of death from the hostile savages who roam to 

 and fro through this region. 



While upon the Rio Mancos, we were presented with specimens of sandstone silver 

 by Mr. John Grigor, who discovered and located a deposit thereof in the Merit district 

 of the Sierra La Sal in Utah. The phenomenal occurrence of the deposition of argen- 

 tiferous mineral in sedimentary matter is not a novelty to geologists, and to its forma- 

 tion allusion were unnecessary. It is of such interest, however, in a mineralogical 

 aspect, that the section although not visited is deemed worthy of note. It need 

 scarcely be repeated that the sedimentary formations outstretching from the bases of 

 the Sierra La Sal are of Cretaceous age. The specimens are very handsome, from the 

 colors of the chlorides, the blue predominating over the green throughout the strati- 

 fication of all the specimens obtained ; they are both high and low grade, the latter 

 giving a mill run of $6 to $8, and the assay of the former equaling $166. 



The inexpensive character of mining operations in such a formation is obvious. An 

 extensive deposit of this nature is reported to have some years since been found in 

 Upper Utah. 



THE ANIMAS DISTRICT 



is situated in the San Juan County and along the river whose name it bears. Half a 

 mile above the mouth of Cunningham Gulch, opening into the Animas River, is the 

 dividing line, we were informed, between this and Eureka District, which lies to its 

 north. It includes mainly, therefore, the mines in the gulches and creeks, reaching 

 the Animas and Baker's Park and those upon the overlooking mountains, chiefly along 

 Cement and Mineral Creeks, Arastra, Boulder, and Cunningham Gulches, and upon 

 Sultan, Anvil, Green, Hazleton, Galena, and King Solomon Mountains. It is the old- 

 est mining district of the San Juan, containing the Little Giant, whose early discovery 

 resulted in the great emigration to the country. It includes some of the most valu- 

 able mines in the valley of the river and within its limits a larger number of lodes 





