National Park Service


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Midwest Archeological Center, Paper presented at the 70th Annual Meeting of the Society of American Archaeology, Salt Lake City, Utah March 30-April 3, 2005


Rockshelters and caves used by prehistoric people have fascinated archaeologists and the general public for many years. Such sheltered locations often contain a wide range of perishable remains as well as intact geological and cultural deposits that make them particularly significant loci for archeological investigation. Rockshelters, caves, and alcoves are often assumed to have served as important locations within past land-use systems. It is the topographic situation, distribution, and domestic activity in proximity to rockshelters along the Purgatoire River in southeast Colorado that is the focus of this paper.

The Purgatoire River flows northeast to the Arkansas River through an area known as the Picket Wire Canyonlands. This component of Comanche National Grasslands (U.S. Forest Service) is bounded on the northwest by the U.S. Army’s Pinon Canyon Maneuver Site (PCMS), an area of approximately 104,000 square kilometers. The landscape is characterized by a semi-arid environment of tablelands, mesas and several canyon systems that drain southeast to the Purgatoire River (Figure 1). A systematic inventory of cultural resources in 7,150 acres of Picket Wire Canyonlands was undertaken in 1993 and 1994 (Reed and Horn 1995). Four of the 263 Native American cultural resource locations documented during that inventory are examined in this study (5LA1023, 5838, 5841, and 5844).1

Rockshelters and “alcoves” are often differentiated from “caves” in archeological literature but less so in ethnographic and ethnohistoric accounts. Characteristics of a “rockshelter” as defined for central Texas by Collins (1991:158) are appropriate for southeastern Colorado where bedrock overhangs and the area beneath is “within reach of daylight and ambient temperature and moisture” (Figure 2). In the study area examined here shelters formed by large boulders have the potential to offer similar characteristics (Loendorf 1989; Loendorf and Kuehn 1991; Reed and Horn 1995).