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Archaeological Investigations at Montaņa de Oro State Park,

San Luis Obispo County, California

Small leaf-shaped projectile points from CA-SLO-9.


This website provides a summary of the archaeological findings from CA-SLO-9. The salvage excavations were completed during two Spring Quarter classes in 2004 and 2005 by Cal Poly field students within Montaņa de Oro State Park in San Luis Obispo County, California. The work was undertaken as part of a partnership established between Cal Poly and the Department of Parks and Recreation. The investigations were undertaken to evaluate the prehistoric site, as it is subject to severe erosion caused by undercutting of the cliff by the Pacific Ocean. The investigations sought to determine the scientific value of the materials being lost. A more complete report on the results of these investigations by Brian Codding and Terry Jones from 2006 is on file at Central Coast Information Center of the California Historic Resources Information System at University of California, Santa Barbara.

Bifacial Notched Stone from CA-SLO-9.

Site Location Map of CA-SLO-9.

Coastal view of Montaņa de Oro State Park in San Luis Obispo County, California  (Photograph by Kenneth & Gabrielle Adelman).

Site Description

CA-SLO-9 is a shell-rich, coastal midden located within Montaņa de Oro State Park. The site is situated on a coastal bluff parallel to the Pacific Ocean. At an elevation of about 40 feet above sea level, the site covers an area of roughly 4000 m2. Historically the site area was impacted by cattle grazing and is currently affected by natural erosion along the western facing cliff. The deposit lies on a coastal terrace and is underlain by alluvial and colluvial sediments derived from low hills. The site was first recorded in the 1960s, and was most recently re-recorded by State Parks personnel in 2001.