155 



that all the rocks of the higher volcanic strata, reaching nearly to the mid- 

 dle of No. 4, contained numerous small particles of pyrite but little decom- 

 posed. The red stratum, asit was named for convenience' sake, is therefore 

 a stratum of volcanic rocks, thoroughly impregnated with pyrite. In 

 those portions where ore-bearing veins have been found, and are worked, 

 I have observed no such impregnation, if we except a few lodes on Min- 

 eral Creek, but even there they are below the red stratum. This fact, 

 unimportant as it might seem at first glance, has a weighty bearing upon 

 the consideration of the ore- veins that have been found in the country 

 that we examined- 



At the time of my visit at the San Juan mines, August and Septem- 

 ber, 1874, but comparatively little work had been done. The greater 

 13ortion of the miners' time and energy was devoted to prospecting, and 

 but a few had then developed their lodes to any extent. One difficulty 

 under which they labored was the want of available capital, and of a 

 place where the ore might readily be converted into cash. It would be 

 impossible to give any fair estimate of the number of men scattered 

 over the country there, but I think that usually given is too high. 



Mining is carried on at several points in the vicinity and on tribu- 

 taries of the Animas Eiver. Near its head, at the so-called " Forks," is 

 a complex of lodes, (one of the early discoveries,) and from it thelocality 

 has received the name " Mineral Point." Traveling down the river for 

 a distance of about six miles Eureka Grulch is reached, another locality 

 considered by the prospectors as very promising. A settlement has 

 been made at Howardsville, on the Animas, this being a point more 

 favorable, perhaps, than many others, having the additional advantage 

 of being centrally located with reference to the mines. At the bend of 

 the Animas, near the base of Sultan Mountain station 26, is Baker's 

 Park proper ; there is a settlement called Silverton. A short distance 

 to the east of Silverton is Arastra Gulch, which became well known 

 some years ago by the discovery of the "Little Giant" mine, and now 

 contains a number of others. In a similar position to Howardsville is 

 Cunningham Gulch, with a number of promising lodes, as yet compara- 

 tively undeveloped. Besides these points, prospecting and mining to a 

 small extent are carried on throughout the entire vicinity, both on the 

 mountains and in the caSons. Smelting-works were in the course of 

 erection at Silverton when visited by our party, but, as I am informed, 

 were not completed satisfactorily. 



Geognostically, the northern portion of the district just described 

 shows scarcely any important variation from the general character of 

 the surrounding country. All the rocks of that part, so far as I have 

 had occasion to observe, are volcanic, exhibiting, as at many other 

 neighboring x)oints, a great variety in texture and mineral constit- 

 uents. From stations 13 and 14, the No. 3 of our schedule, above given, 

 extends west and southwest, changing in lithological character, al- 

 though the stratigraphical relations remain simple. I am inclined to 

 attach considerable importance to this latter feature, all the more so, inas- 

 much as a satisfactory explanation of the geological relation could other- 

 wise only be obtained after very careful detail studies. The rock upon 

 which station 15 is located, is of a grayish to muddy-green color, con- 

 taining small, irregular fragments of a triclinic feldspar, and some 

 sanidite. Cubical pyrite crystals, of about O.S™'" edge, are dispersed 

 throughout the rock, giving it, upon decomposition, a brown color. 



Similar in general character, but varying in detail, are the rocks 

 composing the mountains on either side of the Animas down to Silver- 

 ton, and a short distance beyond. They are mainly aggregates, as 



