The Sisyphus Shelter Archaeological Site was an Archaic period (5500 BCE–150 CE) rockshelter on the northwest side of the Colorado River between Parachute and De Beque. Before the shelter was destroyed by the construction of Interstate 70, it was excavated in 1979–80 by John Gooding and other archaeologists with the Colorado Department of Highways (now the Colorado Department of Transportation). They found evidence of seven occupations dating back to the Middle Archaic period (3000–1000 BCE) as well as a slab-lined habitation floor from the Late Archaic period (1000 BCE–150 CE).

Discovery and Excavation

When Interstate 70 was being planned and built across western Colorado in the late 1970s, archaeological surveys were conducted along its proposed path. In May 1978, the state archaeologist notified the Colorado Department of Highways that the Sisyphus Shelter was significant enough to be eligible for the National Register of Historic Places but would be destroyed by the proposed alignment of the interstate’s westbound lanes near De Beque. As mitigation for the destruction, the Department of Highways and the Bureau of Land Management (which managed the land around the site) performed an extensive excavation of the shelter. Led by John Gooding, the team worked at the site in 1979–80. All artifacts were sent to the University of Colorado Museum of Natural History for curation, and a detailed report was published in 1985 so that information about the shelter would continue to be available despite the site’s destruction.

Description and Significance

The Sisyphus Shelter was in southern Garfield County between Mount Logan and the Colorado River. Like the nearby Kewclaw and DeBeque rockshelters, Sisyphus was about a mile from the river. The site consisted of three distinct habitation areas: area A, a small south-facing rockshelter; area B, an open boulder enclosure; and area C, a large south-facing rockshelter. All three areas were tested, but the excavation focused on area C because it had the most cultural deposits.

Cultural deposits and radiocarbon dates at area C suggested the possibility of seven separate occupations ranging over 4,000 years, from the Middle Archaic period through the Middle Ceramic period (1150–1540 CE). Most of the occupations occurred in the Middle and Late Archaic periods; as the shelter filled with deposits over time, its functional area shrank, and it was used less often.

The excavation team found eighteen hearths and 131 cutting tools at the site, but the most important feature was a slab-lined habitation floor dating to the Late Archaic period. The rectangular floor measured roughly eight by eleven and a half feet and was made of slabs about one to two inches thick. It was found about four and a half feet below the shelter ceiling. No evidence of a superstructure was found, but the people who used it probably erected walls and a roof made of wattle and daub. The floor showed evidence of being used for household activities such as tool production. It would have been repeatedly cleaned and reused.

Because the shelter faced south, it was probably occupied during the winter, when it would have provided warmth from the sun and protection from cold winds. The habitation and many of the hearths were on the edge of the shelter’s dripline, suggesting that the people living there erected a lean-to roof to increase the shelter’s functional space. Building fires at the edge of the shelter would have created a heat shield to keep the interior of the shelter warm.

The Archaic period occupations at the Sisyphus, Kewclaw, and DeBeque shelters were probably all manifestations of the Uncompahgre Complex. When taken together, this cluster of shelters shows that Archaic period hunter-gatherers in this area had a wide range of habitation types: rockshelters with hearths (DeBeque), open sites with architectural features (Kewclaw), and rockshelters with architectural features (Sisyphus).

A long gap between occupations at Sisyphus corresponds with the occupation dates for Kewclaw, suggesting that the area’s inhabitants might have shifted their location and occupation type for some reason at the start of the Late Archaic period. The location of these shelters close to the Colorado River indicates—counter to earlier theories—that the river was a zone of consistent habitation rather than a boundary between different regions.