Stone Enclosures

Enclosures formed by stacked rock walls have been reported from many prehistoric sites in San Diego County, particularly in the Peninsular Range. The ethnohistoric and ethnographic records concerning such features and the archaeological evidence have been discussed by Ronald V. May (1975b, 1975c), Rick Minor (1975b), Joan Oxendine (1981), Richard L. Carrico (1988), and Susan M. Hector (2004).

Minor’s review of archaeological records identified 25 sites, each containing from one to 10 of the features. Carrico reported a complex of 16 enclosures at a site near Rancho Bernardo. On Volcan Mountain alone, Hector recorded nine sites with rock enclosures. According to Minor, the features were always constructed amid natural boulders or bedrock outcrops. The walls are usually 50-120 centimeters high and built by stacking unshaped rocks, without the use of any mortar. A few enclosures are rectangular, but most are circular, typically 2-4 meters in diameter. Most of the enclosures have gaps that could be interpreted as entrances.

According to Minor (1975b:27), “cultural material characteristic of late prehistoric populations is always found either within or in close proximnty.” Although European materials were not reported to be associated with the features, Minor suggested that they were in use during the late nineteenth century, based on a radiocarbon date on charcoal excavated from an enclosure at Kitchen Creek. The date was reported as A.D. 1870 ± 80, presumably 80 ± 80 radiocarbon years B.P. Calibration of this date would give a one-sigma range between A.D. 1680 and 1940, indicating that it could well be prehistoric rather than historic. Hector reported some early historic artifacts associated with a stone enclosure site on Volcan Mountain.

— The interpretation of enclosures as habitation areas is supported archaeologically by the frequent presence within them of midden soil, a variety of lithic tools and debris, pottery, and animal bone. Bedrock milling features are usually also found in association. Malcolm J. Rogers’ site records interpreted the features as residences, and Minor concluded that they were used principally for this purpose. Stephen R. Van Wormer and Carrico (1993) excavated eight rooms within a complex of elliptical or circular enclosures at site SDI-5938, south of Lake Hodges. They recovered 8,485 lithic artifacts (flakes, cores, projectile points, scrapers, utilized flakes, hammers, manos, and metates), 1,069 potsherds, and 5,145 bone fragments, and concluded that the features had been used for habitation.

• Possible ceremonial uses, including functions as dance areas and sanctuaries, were discussed in detail by Oxendine. Minor noted that some enclosures were associated with rock art.
• May argued for the use of enclosures as defensive forts. Florence C. Shipek (personal communication to Minor) also reported belief in this interpretation among modern Kumeyaay. Many of the features are located in elevated positions, with good views of the surrounding terrain. However, Minor noted that many are in indefensible positions.
• The use of the enclosures as hunting blinds is also inconsistent with the positioning of many of the features, according to Minor. Associated habitational debris also argues atainst this interpretation.
• Carrico mentioned the possible interpretation of the features as having functioned as storage areas.

PROSPECTS

Future archaeological investigations may be able provide additional evidence concerning the relation of stone enclosures to habitation sites, ceremonial sites, and locations suited to defensive or hunting use. Excavations may determine how commonly the features contain substantial residues from tool making, food processing and consumption, and ceremonial activities. Replicative experiments may be able to determine the amount of effort and organization that would have been required for their construction.