Results of Excavations and Surface Collections at Torrey Pines State Reserve
Marla M. Mealey
Associate State Archaeologist

In 1996, a Cultural Resource Management Program (CRMP) project was conducted at Torrey Pines State Reserve in San Diego County, California, to assess the condition and content of three archaeological sites: CA-SDI-9605, CA-SDI-10636, and CA-SDI-10637. These three sites, located along eroding bluff edges, contain numerous features and artifacts in danger of being lost due to erosion. Many of the landforms at Torrey Pines contain sandstone bedrock and highly-erosive sandy soils that do not stand up well to the coastal winds, occasional rains, or the hundreds of thousands of people who come to visit the Reserve each year. This project was recommended by State Park archaeologists to investigate the depth, density, and content of CA-SDI-9605, CA-SDI-10636, and CA-SDI-10637 in hopes of increasing our understanding of these sites and their relationships to other sites in the region, before such data are lost forever to the erosional forces threatening them. Funds were also included in this project to provide for radiocarbon dating of site CA-SDI-9605, and for pollen, phytolith, protein residue, and macrofloral (flotation) analyses to determine floral and faunal exploitation and/or seasonality of the sites.

Archaeologists from California State Parks, Southern Service Center, did limited testing and data recovery excavation at sites CA-SDI-9605 and CA-SDI-10637 in April 1996. These two sites were surface collected and mapped, and five 1-x-1-meter units were excavated at site CA-SDI-9605. Investigations at the third site (CA-SDI-10636) were limited to site recordation and feature mapping.

Image of location map      Image of eroding bluffs   

Image of site 
    Image of erosion damage 


The test excavation and surface collections at CA-SDI-9605 produced a total of 338 pieces of prehistoric cultural material. The artifacts that were recovered included 267 pieces of stone tool manufacturing waste, 3 hammerstones, 11 stone cores, 1 mano (hand stone) fragment, and 2 bifacially-flaked stone arrow or knife points. A total of 364.61 grams of shell was also recovered.

The surface collection at CA-SDI-10637 produced a total of 113 prehistoric artifacts including 106 pieces of stone chipping waste, 2 stone cores, 1 hammerstone, 1 stone anvil, 1 metate (grinding stone), and 2 mano (hand stones). Additionally, 4,220 pieces (1684.06 grams) of shell were also recovered.

Image of surveyor    Image of test excavation 
   Image of unit 5   Image of feature 1

Illustration of mano          Illustration of hammerstone          Illustration of lithic core          Illustration of bifacial points          Illustration of metate

Twelve clusters of fire-affected rock and burned soil were recorded at CA-SDI-9605 and more than thirty-five at CA-SDI-10637. Thirteen fire-affected rock features were also recorded at CA-SDI-10636. Fire-affected rock features have been interpreted by various researchers as hearths, ovens, or "roasting platforms" possibly for the processing of Torrey pine seeds or other edible plants. Previous testing of fire-affected rock features in Torrey Pines State Reserve has resulted in dates of AD 800 (Reeves 1982) and less than 300 years old (Barter 1987).

Image of stone anvil      Image of fire-affected rock     Image of clam

Half of a Washington clam (Saxidomus nuttalli) from the 20- to 30-cm level of Unit 3 at CA-SDI-9605, a sample of charcoal from the 40- to 50-cm level of Unit 3, and a single piece of charcoal from the 10- to 20-cm level of Unit 2, were sent to Beta Analytic in Florida for radiocarbon dating purposes. The calibrated results of this testing returned dates of AD 345 to 670 for the shell sample, AD 430 to 660 for the Unit 3 charcoal sample, and AD 1395 to 1470 for the Unit 2 charcoal sample. These dates are comparable to previous dates for this site and the other sites that were tested during this project.

Seven artifact and soil samples were sent to Paleo Research Laboratories (Paleo) in Colorado for floral analyses including pollen, protein residue, and phytolith studies. A small concentration of fire-affected cobbles and associated charcoal was found in Unit 2 at CA-SDI-9605 and was designated Feature 1. A soil sample from below this Feature was also sent in to Paleo for pollen and phytolith analyses and macrofloral flotation procedures to attempt to recover burned seeds or other charred plant materials.  The pollen spectrum for the Feature 1 soil sample was dominated by high spectrum Asteraceae (asters, sunflowers, etc.) pollen. The next most common pollen type was Artemisia sp. (sagebrushes) and indeterminate pollen, followed by smaller quantities of Alnus sp. (alders), Juniperus sp. (junipers), Pinus sp. (pines), Quercus sp. (oaks), low spine Asteraceae (weedy members of Sunflower family), Liguliflorae, Eriogonum sp. (California buckwheat), Lamiaceae (black sages, white sages, chias), Onagraceae (evening primroses, California peonys), Poaceae (grasses, bromes), Rhamnaceae (California lilacs, buckthorns), and Selaginella sp. (club mosses, ferns) [Scott Cummings et al. 1996:9].  The sample did not appear to be contaminated by historic or modern pollen, but it also did not appear to contain "any evidence suggestive of plant utilization at the site" (Scott Cummings et al. 1996:9). The macrofloral study resulted in the recovery of a charred Sage seed (Salvia sp.), an uncharred Convulvulaceae seed (morning glory family), charred dicot leaf fragments, and charcoal from the Asteraceae family. Two bifaces that were collected at CA-SDI-9605 prior to this study (P1141-00-170 and P1141-00-171) were also sent in to Paleo for protein residue analysis. The results for these two artifacts were negative.

In addition, two groundstone samples (P1143-00-10 and P1143-00-11) from site CA-SDI-10637 were sent to Paleo for phytolith and protein residue analyses. A comparison of the soil control samples (taken adjacent to each artifact) with the phytolith wash results, appears to indicate that both the mano (P1143-00-10) and the metate fragment (P1143-00-11) were used to grind grass seeds (Scott Cummings et al. 1996:7-8). The metate fragment also yielded a positive protein residue result for deer antiserum (Scott Cummings et al. 1996:8). The corresponding soil control sample tested negative to all antisera, suggesting that the positive result on the metate fragment was not due to soil contamination (Scott Cummings et al. 1996:8). It is possible that deer hide, meat, sinew, or bone was processed on the metate.

These results indicate that CA-SDI-9605 was inhabited during the early and middle parts of the Late Prehistoric Period, which lasted from circa AD 500 to European contact. The excavations at CA-SDI-9605 show the site to have evidence of shellfish processing and tool manufacture. The test results from the hearth feature were inconclusive in determining its specific use. The surface collection at CA-SDI-10637 show that similar activities were carried out there with the addition of grass seed milling as evidenced by the positive result from the phytolith analyses of the mano and metate, and processing of deer hide, meat, sinew, or bone.

Additional studies have been carried out over the last nine years at Torrey Pines State Reserve, including other excavations, construction monitoring, archaeological surveys, and site recordation. With each new project, new information is recovered to help increase our understanding of the archaeological sites and those who once lived in this region. Although other fire-affected rock features have been tested, there is still no definitive evidence to indicate what, if anything, was being processed, cooked, or roasted in these hearths, ovens, or roasting platforms. But we will continue conducting research and hopefully one day we will have a better understanding of their purpose.


Barter, E. R.
1987 CA-SDI-10636, The Cache Site, Torrey Pines State Reserve: A Report of Work Conducted Under Statewide Resource Management Program Project 403-630-3-2. State of California,
Department of Parks and Recreation. On file, DPR, Southern Service Center, San Diego.

Reeves, B. O. K.
1982 Torrey Pines Reserve, A Brief Report. University of Calgary, Alberta, Canada.
Submitted to California Department of Parks and Recreation. On file, DPR, Southern Service Center, San Diego.

Scott Cummings, L., K. Puseman, T. Moutoux
1996 Pollen, Phytolith, Macrofloral, and Protein Residue Analysis at Sites CA-SDI-10637, CA-SDI-9605, and CA-LAN-92, Southern California. Paleo Research Laboratories. Prepared for California Department of Parks and Recreation. On file, DPR, Southern Service Center, San Diego