Archaeological Investigations at Montaña de Oro State Park,

San Luis Obispo County, California

Conclusions

Research of the last four decades has greatly improved our understanding of the archaeology and prehistory on the central coast of California. Findings from CA-SLO-9 also further our understanding of central coast prehistory not by illuminating the oldest, longest, or most intensive occupation, but by the presence of a discrete component occupied during a period associated with unusual climatic patterns. Data from CA-SLO-9 allows for refinement of the Middle-Late Transition Period as defined in the regional culture history, while at the same time, the site findings also provide an opportunity to evaluate the possible effects of climatic variability on local populations.

Coon Creek Phase

The combined results of the chronometric analyses and typological evaluation of shell beads indicate an extremely cohesive chronology for CA-SLO-9 that has important implications for local and regional culture history. The site represents a single Middle-Late Transition component dating from ca. A.D. 900-1300. The assemblage from this site is typologically consistent with the chronometric data and provides a basis for defining a Coon Creek Phase as a local expression of the Middle-Late Transition in the San Luis Obispo area.

Based on findings from MNT-1233 and MNT-281,  the Highland Phase (A.D. 1000-1200)was developed to define the Middle/Late Transition Period in the Big Sur district. As with the Highland Phase, beads from the Coon Creek Phase are marked by the co-occurrence of Middle Period and Late period types, and also lack the Split-punched bead (Class D) and the M1a sequin rectangle. Specifically, the SLO-9 assemblage is dominated by Normal Saucers (G2), accompanied with a Tiny Saucer (G1) and two cupped beads (K1). Missing from the Highland Phase, but present at CA-SLO-9  is a single Steatite Disk, which generally dates to the Late period on the central coast, which only adds to the picture of the Middle-Late Transition as a clear blend of two cultural horizons.

Projectile point types were dominated by the contracting stemmed type, which is most frequently associated with the Middle Period; many examples have been recovered from Early Period sites. A single specimen from CA-SLO-9 was made from shale, which highlights the importance of siliceous shale as a tool stone. Small leaf-shaped points were the second most common type at CA-SLO-9 and are thought to also mark the Middle-Late Transition. While they are commonly interpreted as early arrow points, they may have served as tips for harpoons. The other two types recovered from SLO-9 are represented by single examples: a double-side notched point and a large side-notched point. While the recovery of the former helps to confirm that this type indeed marks the Middle-Late Transition, the recovery of the latter is thought to mark the early Holocene.

The recovery of notched stones supports the possibility that these artifacts mark the Middle-Late Transition on the central coast. The co-occurrence of these artifacts with circular shell fishhooks at CA-SLO-9 seems to indicate their association.

While the single-piece circular shell fishhooks is certainly older in other regions of California, the large number found at CA-SLO-9 may represent the  emergence of hook and line fishing as the dominant technique along the San Luis Obispo coast during the Middle-Late Transition. Nine specimens were recovered from CA-SLO-9.

Bone tools at SLO-9 are marked by awls, a bi-pointed object and an absence of gorges. The awl fragments were typical for the central coast and the bi-pointed specimen is somewhat unique in its morphology and could have served one several alternative purposes.

In summary, findings from CA-SLO-9 indicate that the Middle-Late Transition in San Luis Obispo County is marked by a co-occurrence of traits from the Middle Period and Late period. These findings are in line with those for the Middle-Late Transition in the Big Sur region at CA-MNT-1233 and help to further clarify cultural chronology in the San Luis Obispo coastal district. Further, the abandonment of CA-SLO-9 at about A.D. 1300 is significant as it supports previous arguments for widespread site abandonment during the Medieval Climatic Anomaly.

 

 

Artifacts from CA-SLO-9 marking the proposed Coon Creek phase.

Summary of formal artifact assemblage from CA-SLO-9

Faunal Remains & Diet

The mammal and bird bone assemblage from CA-SLO-9 shows a diverse diet dominated by rabbit (species combined; NISP = 37, 27.1%), cormorant (Phalarocorax sp.; NISP = 30, 21.9%), and sea otter (Enhydra lutris; NISP = 18, 13.1%). Looking at the broad classes, the collection was dominated by terrestrial mammals (NISP = 74, 54%), followed by birds (NISP = 41, 29.9%) and marine mammals (NISP = 22, 16.1%).  This assemblage differs significantly from CA-SLO-267 which was dominated by black-tailed deer (NISP = 88, 31.4%) with little contribution from birds or marine mammals (Jones and Ferneau 2002). However, the dominance of rabbits is consistent with other Middle-Late Transition assemblages near the Monterey Peninsula and in the San Francisco Bay area. While some may argue that this dietary shift represents an intensified, sub-optimal diet, it may in fact represent the unavailability of any higher ranked taxa due to droughts. The increased reliance on marine birds and mammals further justifies this supposition. Recent research shows that the Middle-Late Transition is marked not only by droughts, which may have decreased the productivity of the terrestrial environment, but also by increased upwelling, which may have ramped up marine productivity. If this is the case, the occupants of CA-SLO-9 may have adapted to these conditions by focusing more on low-ranked, highly fecund terrestrial resources and the marine environment. Fish remains from CA-SLO-9 were dominated by rockfish (NISP=292; 44%), and cabezon (NISP=192; 29%), followed by senorita (NISP=46; 7%), surfperch (NISP=40; 6%), and pricklebacks/monkeyface (NISP=33; 5%). Cabezon and rockfish also dominate the assemblage when ranked by MNI (combined=295; 78%) and weight (combined=70.16; 90%). This high percentage of large, possibly line caught taxa runs contrary to the fish remains recovered from both CA-SLO-267 and CA-SLO-179, where a higher number of smaller species are represented even among the control units. These findings are in line with the large number of shell fishhooks recovered, as the equation of cabezon and rockfish without significant numbers of smaller taxa could only come from a hook and line technology. The results of the shellfish analysis show that over 70% of the invertebrate taxa exploited at CA-SLO-9 were either mussel, abalone, or urchin; with a primary reliance on mussel (32.68%) and abalone (31.92%), followed by urchin (11.79%), barnacle (8.45%), turban snail (6.79%) and chiton (4.26%) (See Table 5.10). The two highest ranking species, mussels and abalone, were also subjected to size-frequency analysis, which showed that occupants of CA-SLO-9 harvested mussels with a stripping strategy, and that the average size of mussels from SLO-9 was significantly larger than at CA-SLO-267, indicating either less pressure from humans or a more favorable environment for mussels. 

Seasonality, Mobility & Exchange

The nature of settlement strategies vis-à-vis seasonal group movements and resource exploitation schedules continues to be unclear for the central California coast. At CA-SLO-267, Jones and Ferneau cautiously accepted a proposal advanced previously by Mikkelsen et al. suggesting a bipolar settlement system in which foragers split their time between coastal and interior residential bases, occupying the coast from fall through winter and traveling to the interior in the spring where they resided through the summer, returning to the coast again in the fall. Estimates of the season of collection at CA-SLO-9 were made for 13 mussel shells from a total of 63 isotopic readings. Sea-surface temperatures recorded in the carbonate of the samples ranged between 10.28ºC and 15.58ºC, suggesting that seas may have had higher lows and lower highs at CA-SLO-9 when compared with the historic range of 9.86 ºC to 17.39 ºC recorded at Hopkins Marine Life Station in Pacific Grove. In previous syntheses of central coast prehistory, a suggestion has been made that inter-regional exchange, marked by obsidian from eastern Sierran sources, deteriorated during the Middle-Late Transition. Findings from CA-SLO-9 show that this is not entirely accurate. A total of 26 pieces of obsidian was recovered from an excavation volume of 23.7 m3, representing 1.1 pieces/m3. While this is a low figure, it is higher than the density of obsidian at CA-SLO-267. It is also considerably greater than the figures associated with post- Middle-Late Transition (Late Period) occupations within Fort Hunter-Liggett. As a working hypothesis we suggest that the apparent breakdown in exchange occurred at the end of the M-L Transition ca. A.D. 1250-1300 coincident with the abandonment of CA-SLO-9. Also of note, CA-SLO-9 produced one piece of Grimes Canyon fused shale which is commonly traced to a source or sources further south in ethnographic Chumash territory. While the occurrence of this piece at CA-SLO-9 speaks to interactions between groups within the ethnographic language territory, the low frequency of the material does not support the idea of extensive north-south exchange.

Flaked Stone Technology

The flaked stone tools and debitage from CA-SLO-9 represent a typologically and technologically cohesive assemblage. Typologically, projectile points recovered from CA-SLO-9 are typical of the Middle-Late Transition period on the central coast, which is marked by the co-occurrence of contracting-stemmed and small-leaf-shaped points. The recovery of a double-side notched point further supports this chronological distinction. However, while the recovery of a single large-side notched point may seem inconsistent with this dating, it is possible that this type persists into the Middle-Late Transition. Technologically, the flaked stone debitage and artifacts are mutually concordant with respect to the types of stone reduction activities they suggest. The recovery of cores, debitage and all stages of bifaces show that all phases of stone tool production took place at this location. The inhabitants of CA-SLO-9 emphasized local tool stone, particularly Monterey chert and shale for the manufacture most tools, particularly bifaces, projectile points and notched stones.

SUMMARY: THE MIDDLE-LATE TRANSITION AT CA-SLO-9

The portion of CA-SLO-9 investigated in 2004 and 2005 marks an extremely cohesive component dating cal A.D. 900-1300. The Middle-Late Transition is generally dated ca. A.D. 1000-1250 in central and southern California and the CA-SLO-9 findings serve to refine characterization of this important period in the San Luis Obispo area. Typologically, the proposed Coon Creek Phase is marked by co-occurrence of contracting-stemmed, double side-notched  and small leaf-shaped projectile points, G2 Olivella saucer beads, K1 Olivella Cupped beads, circular shell fishhooks, and distinctive notched stone fishing weights. The latter were probably used together with the hooks as line weights in hook and line fishing. The phase is also distinguished by the absence of pitted stones which are ubiquitous in earlier contexts. With the exception of the notched stones and double side-notched points which seem to be distinctive Middle-Late Transition traits, none of the other artifacts are restricted to the Middle-Late Transition, but also occur in either the Middle (contracting-stemmed projectile points, G2 Olivella saucer beads) or Late (K1 Olivella Cupped beads, circular shell fishhooks) periods. In this regard, the Coon Creek Phase indeed seems to mark an overlap between the Middle and Late Periods although it shares more traits with the former and might be best conceptualized as the terminal Phase of the Hunting Culture in the San Luis Obispo area of the central coast.

References Cited

Hylkema, M. 2002 Tidal Marsh, Oak Woodlands, and Cultural Florescence in the Southern San Francisco Bay Region. In Catalysts to Complexity: Late Holocene Societies of the California Coast. Edited by J. M. Erlandson and T. L. Jones, pp. 233–262. Institute of Archaeology, University of California, Los Angeles.

Jones, T. L.  1993 Big Sur: A Keystone in Central California Culture History. Pacific Coast Archaeological Society Quarterly 2. Pacific Coast Archaeological Society, Costa Mesa.

Jones, T. L.  1998     Archaeological Data Recovery at the Toro Creek site, CA-MNT-3, Monterey County, California. California Department of Transportation, Sacramento. Copies available from the Northwest Information Center of the California Historical Resources Information System, Sonoma State University, Rohnert Park.

Jones, T. L., and J. A. Ferneau 2002  Prehistory at San Simeon Reef: Archaeological Data Recovery at CA-SLO-179 and -267, San Luis Obispo County, California. San Luis Obispo County Archaeological Society Occasional Papers No. 16. San Luis Obispo.

Jones, T. L., and J. W. Haney  2005         Archaeological Evaluation of CA-MNT-910, -1748/H, 1919, and –2182, Fort Hunter Liggett Military Installation, Monterey County, California. California Polytechnic State University, San Luis Obispo. Copies available from Northwest Archaeological Information Center, Department of Anthropology, Sonoma State University, Rohnert Park, California.

Jones, T. L., G. M. Brown, L. M. Raab, J. L. McVickar, W. G. Spaulding, D. J. Kennett,    A. York, and P. L. Walker  1999 Environmental Imperatives Reconsidered, Demographic Crises in Western North America during the Medieval Climatic Anomaly. Current Anthropology 40:137–170.

Kennett, D. J., and J. P. Kennett  2000 Competitive and Cooperative Responses to Climate Instability in Coastal Southern California. American Antiquity 65:379–395.

Mikkelsen, P., W. R. Hildebrandt, and D. A. Jones  2000 Prehistoric Adaptations on the Shores of Morro Bay Estuary: Excavations at Site CA-SLO-165, Morro Bay, California. San Luis Obispo County Archaeological Society Occasional Papers No. 14. San Luis Obispo.