Notes on a Great Silver Camp. 407 
tinental divide have never been entirely resubmerged, but 
since their first upheaval on the contracting of the cooling 
earth crust their summits have ever borne the brunt of 
attack from the waves and storms of all the succeeding 
_ ages. Over many miles in Colorado and Utah these ore- 
bearing limestones have been traced, and found sometimes 
lying nearly flat, as at Leadville, or else dipping steeply, 
almost vertically, as at Mount Snow, Mass., the outcrop pre- 
senting in places bold, precipitous escarpments towards the 
main range. Thousands of mining ,claims have been and 
still are being located, but not everywhere does it appear 
that the mineral depositing conditions have prevailed, 
although each year develops new areas along this horizon, 
and established mining districts extend farther along as 
new mines are discovered, some of wonderful extent and 
richness. 
In 1879 these prospectors crossed over through Inde- 
pendence Pass to the west side of the Sawatch range, the 
mountains of Archean rock, and followed the Roaring Fork 
river in a north-westerly direction down a valley with 
granite exposures rising high on either side, to where the 
river cuts across nearly at right angles the steeply inclinal 
Paleozoic strata, which in the direction of their strike, 
northeast and southwest, resting upon the granites, rise 
rapidly on each side of the valley to form Smuggler Mount 
on the northeast and Aspen Mount on the southwest. On 
the former mountain there is a thickness of 600 feet of 
detrital matter or wash, with only the granite and quartz- 
ite exposed, with few or no indications of ore-bearing rocks, 
excepting a mass of sinter-like dolomite at the base that 
assayed well in silver, and was located as the “Smuggler ” 
claim. But up Aspen Mount runs Spar Gulch, having on 
the south-east quartzite, and on the northwest a steep lofty 
wall comprising the upturned edges of the Silurian dolo- 
mite and the Lower Curboniferous limestones, the trail in 
the bottom of the gulch following along the junction of the 
quartzite and dolomite. Ore was found on this mountain, 
and at its base now lies the town of Aspen, the prettiest and 
