Geomorphology and Prehistoric Site Distribution Near Hamilton City, California, and Their Implications for the Archaeological Record of the Sacramento Valley

ABSTRACT

Despite more than a century of investigations, archaeologists have found few prehistoric sites over 3,000 years old in California’s Central Valley. Yet, recent surface inventory, geoarchaeological trenching, and archaeological excavations along the Sacramento River near Hamilton City, California, identified 10 archaeological sites and 15 occupational components spanning the last 7,000 years. Half of these components occurred solely in buried contexts. Five were over 2,500 years old and include some of the earliest evidence for human occupation in the Sacramento Valley. Importantly, several key sites occur in contexts mapped as Pleistocene-aged, Modesto deposits. These results underscore the role discovery bias may play in structuring the archaeological record of the Sacramento Valley and the need for more careful assessment of the geomorphological setting and age of potential deposits when approaching archaeological investigations.

RESUMEN

A pesar de más que un siglo de investigacións, arqueólogos han encontrado pocos sitios arqueológicos con más que tres mil años de edad. Sin embargo, investigaciones y excavaciones por el Rio Sacramento cerca Hamilton City, California identificaron 10 sitios arqueológicos y 15 componentes ocupacionales abarcando los últimos 7,000 años. La mitad de estos componentes ocurrieron solamente en contextos enterrados. Cinco tenían más que 2,500 años de edad y incluyen algún de la evidencia más temprana por ocupación humana en el Valle de Sacramento. Discutimos el contexto geomorfológico de estos descubrimientos en relación con su edad y el sesgo observado en la distribución temporal de sitios en el Valle Central además de las claves para identificar sitios tempranos en contextos similares.

KEYWORDS:

• Geomorphology
• geoarchaeology
• buried sites
• Pleistocene
• Holocene
• Hamilton City Project
• Sacramento valley
• Sacramento river

Acknowledgments

We would like to acknowledge geoachaeologists Phil Kaijankoski and Naomi Scher for their hard work during the initial phases of the investigations; Richard Perry, Joe Griffin and Geneva Kraus of the U.S. Army Corps of Engineers for shepherding the project; and Kyle McHenry and the Mechoopda Indian tribe of Chico Rancheria for their interest and participation. The comments of two anonymous reviewers helped to improve our final manuscript. Any shortcomings, errors, or omissions remain ours. While much of the fieldwork summarized in this article was conducted on behalf of the U.S. Army Corps of Engineers, the views expressed are those of the authors and not necessarily those of the Corps of Engineers or any of its components.

Disclosure Statement

No potential conflict of interest was reported by the author(s).