The Clark Creek Cache in West-Central Montana

Abstract

The majority of Precontact lithic caches from Montana cannot be chronologically placed, because they lack primary context with radiometrically datable organics or are not composed of obsidian, a datable natural glass. Dated obsidian from caches can also be positively traced to its geologic source. A rare such cache of largely obsidian pieces was found on the Sieben Ranch in 2011. Forty-three obsidian flakes and four chert flakes were observed partially exposed inside a 21-cm-diameter pit. X-ray dispersive fluorescence analysis attributed obsidian to the Bear Gulch source in the Centennial Mountains area of southwestern Montana and southeastern Idaho, approximately 280 km distant. Hydration dating suggests that the caching event occurred c. 444 ± 18 hydration years before present (HYBP). The unidirectional core technology applied to produce the majority of the pieces and the resulting large, curved, blade-like, retouched flakes is unexpected for the Late Precontact Period in the Northern Plains and Intermountain Regions.

Keywords:

• Lithic cache
• Obsidian
• Northern Plains

Acknowledgments

Troy Helmick illustrated selected artifacts from the Clark Creek Cache. Richard Hughes determined trace element chemistries for five of the obsidian artifacts. Tom Origer measured the thickness of the hydrated bands of those same five pieces and calculated hydration ages (HYBP). John and Nina Baucus graciously allowed the authors to examine the core and the pieces recovered from the cache pit, and underwrote the cost of instrumental analyses. This effort makes a positive contribution to the regional archaeological record, and, at the same time, enriches knowledge of the body of cultural resources available on the Sieben Ranch.

Notes on Contributors

Patrick J. Rennie developed an interest in archaeology while hunting for “arrowheads” at a very early age. One of his specific interests is the location of tool stone sources and the cultural translocation of those materials. He earned his B.A. from Montana State University and his M.A. from the University of Montana (anthropology), and has worked professionally in both the private and public sectors. For the past 21 years he has served as the archaeologist for State Lands in Montana.

Leslie B. Davis (December 7, 1935–October 7, 2014) received his B.A. (1959) and M.A. (1969) in cultural anthropology from University of Montana, Missoula. In 1972 he received his Ph.D. from the Department of Archaeology, University of Calgary with a dissertation on The Prehistoric Use of Obsidian in the Northwestern Plains. He would continue research into the prehistoric use of obsidian the rest of his life, and published over 150 articles and manuscripts on Northern Plains archaeology. He retired (Professor Emeritus) from Montana State University in 2007.