THE SAN JUAN REGION. 191 
is that the narrow-gauge coaches of the Denver & Rio Grande will be taxed to 
their utmost in carrying prospectors and capitalists to the prospectively rich 
regions of southwestern Colorado. 
‘<The formation containing the lodes, aud holding the greatest portion of 
the mineral belt,” says the Denver (ews, ‘‘is in and around San Juan County, 
and the formation, generally speaking, is eruptive or volcanic porphyry, with 
granite and occasionally sandstone and trachyte, as the country rock and vein 
walls. Silver predominates asa galena ore, carrying from ten to twenty per 
cent. of lead, and ranging from fifty ounces upward to the ton. Gray copper, 
ruby silver, wire and native silver, carbonates, sulphurets, chlorides and free gold 
are the other ores found throughout the district.” 
The Summit district, in Rio Grande County, is exclusively gold, free and in 
decomposed quartz, with stamps as the only process of treatment. Henson 
Creek and Sheffer’s Basin, in Hinsdale County, Uncompahgre and Poughkeepsie 
districts, with Mount Sneffles and a portion of the Upper Miguel and Silver Moun- 
tain, in Ouray County, forming a regular belt of mineral, have a high-grade gray 
copper ore, with ruby, wire, native and brittle silver, carrying little lead, and 
hence suitable for the leaching, or lixiviation process. The veins on Mounts 
Galena, Tower, Hazelton, Aulton, King Solomon and Kendall, in San Juan 
County, surrounding Silverton, are essentially galena ore bearing, averaging as 
much as fifty per cent. in lead. These ores are treated by reverberatory roasters 
and cupola blast furnaces. The main stream of the San Miguel, in Ouray 
County, and the La Plata River, in La Plata County, are altogether placer and 
gulch diggings, mined by sluice booming and hydraulics. The latest discovery 
on the Dolores, in Ouray County, properly called the Pioneer district, for it was. 
worked years before the most of the San Juan Region was known, is now exclu- 
sively a carbonate camp, with the same formation and general characteristics as. 
Leadville, except, perhaps, less lead, more iron, and an altitude 3,000 feet lower. 
The notable districts now are comparatively scattered, and there are forty miles 
square webbed with mineral veins, all, as yet, barely prospected. 
As nearly as can be estimated, the ore product of the mines in this district, 
last year, amounted to 9,075 tons, or $1,400,000. The present year a very great 
increase is confidently predicted. Smelting furnaces and reductionand sampling 
works will be erected at many points. The hundred or more mines discovered 
last year will be developed and worked this year. Capital is already seeking 
investment here, and the outlook for activity all along the line could not be 
better. 
SILVER CLIFF AND ROSITA. 
The tourist will do well to make a visit to the famous mining camps, Rosita 
and Silver Cliff, before leaving this section of Colorado. Stages from Cafion 
City make daily trips to these points and enable sight-seers to see the two most 
populous as well as richest mining camps of southern Colorado. Rosita is eight 
miles beyond Silver Cliff and two years ago was the scene of a great rush. It. 
