Evidence for 18 ka Human Occupation at Rimrock Draw Rockshelter, Harney County, Oregon

Evidence for 18 ka Human Occupation at Rimrock Draw Rockshelter, Harney County, Oregon

Dr. Patrick O'Grady
Bureau of Land Management, Burns District, Oregon

Rimrock Draw Rockshelter (35HA3855) is a small and shallow rockshelter located in Harney County, Oregon at the north edge of the Great Basin. Situated in wide-open sagebrush steppe country, the location looks much like a thousand other nearby places where one might expect to find stone tools dating from the mid- to late-Holocene. However, the archaeological record at this site ends around 7,000 years ago, shortly after the cataclysmic eruption that formed Crater Lake from Mount Mazama, and human occupation of the site begins much earlier. Dates of 18,000 to 17,000 years before present have been obtained through high precision Accelerator Mass Spectrometry radiocarbon assays (AMS14C) on Camelops and Bison tooth enamel fragments collected from deeply buried archaeological deposits. The teeth are associated with stone tools and chipping debris indicating human contemporaneity at the site. Other evidence suggests that several genera of Pleistocene herbivores were butchered and consumed there. This presentation will include an overview of fieldwork at the rockshelter to contextualize the provenience of the dated enamel fragments.

Dr. Patrick O'Grady earned his BS, MS, and Ph.D. from the University of Oregon and worked for their Museum of Natural and Cultural History from 2005 until 2023. Before that, he worked for the Oregon Department of Transportation as a highway archaeologist. He is currently the District Archaeologist and Tribal Liaison for the Burns District Bureau of Land Management in southeastern Oregon where much of his research has been centered. Dr. O’Grady’s focus over the years has been on hunter-gatherer adaptations, Paleoamerican archaeology, geophysical field applications, and zooarchaeology, including the development of a substantial comparative osteological collection for the University of Oregon.

Presented to the Pacific Coast Archaeological Society (PCAS) on May 9, 2024.

For additional information on the Pacific Coast Archaeological Society, see the PCAS website at www.pcas.org