Uncompahgre Cirque

Uncompahgre Cirque is a quarry workshop located at 3,840 m (12,600 ft) on the flank of Uncompahgre Peak. The site consists of a dense concentration of flaking debris and chipped stone tools covering more than a hectare. PCRG’s investigation at the site, a cooperative project jointly carried out with the U.S. Forest Service and funded in part by History Colorado’s State Historical Fund, included small-scale hand excavation, intensive surface mapping, and targeted surface collection.

Multiple lines of evidence together indicate that the site was occupied briefly between about 5,900 and 5,700 years ago. All four radiocarbon dates from the site are statistically equivalent, yielding a weighted mean age of 5038±19 ¹⁴C yr B.P. Obsidian artifact hydration data point to a brief occupation or short series of brief occupations within this period, as do stratigraphic data. The presence of well-defined chipped stone features primarily representing the reduction of individual raw material nodules testifies to the remarkable integrity of the site’s cultural deposits.

The principal activity at Uncompahgre Cirque was reduction of chert nodules quarried on a high, narrow ridge close to the site. Blanks prepared for off-site transport and use include large flakes, multi-directional cores, and both early- and late-stage bifaces. Flintknappers at Uncompahgre Cirque also manufactured a variety of tools for on-site use. Some of the tools produced from local stone for on-site use were made from heat-treated flakes or nodules.

A notable feature of the workshop is the presence of cores, tools, and flaking debris made from non-local raw materials. The diversity of imported raw materials suggests that multiple groups from different regions came together to use the chert quarry at Uncompahgre Cirque.

Download 2012 Report

Colorado Archaeology 2012 Article (Abstract Only)

2012 Mitchell, Mark D. A High-Altitude Quarry Workshop in the Northern San Juan Mountains. Colorado Archaeology 78(1):10-15.
Copies of this issue can be ordered from the Colorado Archaeological Society.