The Geochronological and Geoarchaeological Context of the Clovis-Age La Prele Mammoth Site (48CO1401), Converse County, Wyoming

ABSTRACT

The La Prele Mammoth site (48CO1401), located in Converse County, Wyoming, contains a Clovis-age occupation associated with the remains of a subadult mammoth (Mammuthus columbi). In this paper, we present the geochronological and geoarchaeological context of the site. The La Prele Mammoth site is buried in an alluvial terrace of La Prele Creek, a tributary of the North Platte River, which acts as an important migration corridor through the Rocky Mountains. Archaeological remains, buried by a series of flood deposits, occur within or below a well-developed buried A horizon, referred to as the Mammoth Soil. Bioturbation of the site has resulted in vertical artifact movement, though peaks in artifact density are evident in vertical artifact distributions and likely represent the occupation surface. Radiocarbon dating of this occupation, including several new dates, suggests an age of 12,941 ± 56 calendar years ago (cal yr BP).

KEYWORDS:

• Clovis
• geochronology
• radiocarbon
• Wyoming
• northwest Plains USA

Acknowledgements

We are grateful to landowners Jim and Rea Strock for the opportunity to work on the site. Jack Amen, Zach Amen, and James and Shirley Baker have been helpful throughout the duration of the project. Vance T. Holliday and two anonymous reviewers provided comments that helped to improve both the content and clarity of this manuscript.

Disclosure statement

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

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Notes

1 All sediments were water screened through 1/16” mesh.

2 The presence of particulate coal throughout T3 alluvium suggests La Prele Creek, which cuts through Fort Union Formation locally, is the source of all sediment, and not the North Platte River.

3 Allostratigraphic units differ from lithostratigraphic units in that the timing of the accumulation of the unit is considered, and are not solely defined on the basis of lithology.

4 We add one to artifact counts because these values exhibit a log-normal distribution, and adding allows for the inclusion of levels with zero artifacts in them in parametric correlation.

5 We exclude Block A because artifact counts are too low to use this method.

6 ASI Indexes for each block are calculated using the following artifact counts for 5 cm levels: Block B, 0, 3, 8, 18, 23, 6, 3; Block C, 0, 7, 24, 24, 9, 3; Block D, 0, 7, 105, 189, 753, 424, 19, 15, 13, 9, 12, 1.

Additional information

Funding

This work has been supported by the National Science Foundation (grant number 1947297), National Geographic Society (grant number 9896-16), the Wyoming Cultural Trust Fund (grant number 212-17-S), the Quest Archaeological Research Program, the George C. Frison Institute of Archaeology and Anthropology, the University of Wyoming Archaeological Field School, and the Roy J. Shlemon Center for Quaternary Studies.

Notes on contributors

Sarah A. Allaun

Sarah A. Allaun is a PhD candidate at the University of Wyoming. She received her MA in Anthropology from the University of Wyoming in 2019. Her research interests include geoarchaeological and geochronological problems related to the hunter-gatherer archaeology of Pleistocene North America.

Todd A. Surovell

Todd A. Surovell is a Professor of Anthropology and Director of the George C. Frison Institute of Anthropology and Archaeology at the University of Wyoming. His primary research interests include human behavioral ecology, hunter-gatherer archaeology, geoarchaeology, and ethnoarchaeology.

C. Vance Haynes

C. Vance Haynes is a Regents Professor Emeritus of Geology and Anthropology at the University of Arizona. His primary areas of specialization are Quaternary geology and Paleoindian geoarchaeology.

Spencer R. Pelton

Spencer R. Pelton is the Wyoming State Archaeologist. His research primarily focuses on the early prehistory of hunter-gatherers in the High Plains and Rocky Mountains of the American West, but he also maintains research interests in geoarchaeology, site formation, chronological modeling, experimental archaeology, and global human dispersal.

Madeline E. Mackie

Madeline E. Mackie is an Assistant Professor of Anthropology at Weber State University who specializes in western North American hunter-gatherers. Her research interests include the early inhabitants of North America, quantitative methods, spatial analysis, and big game hunting.

Robert L. Kelly

Robert L. Kelly is a Professor of Anthropology at the University of Wyoming. He is an expert in hunting and gathering societies, both present and past. His archaeological research focuses on the American West.

Matthew O’Brien

Matthew O’Brien is an Associate Professor of Anthropology at California State University, Chico. His primary focus in archaeology is the study of North American hunter-gatherers.

Paul H. Sanders

Paul H. Sanders is a retired Director of the Archaeological Survey in the Office of the Wyoming State Archaeologist. He has expertise in the archaeology of the Rocky Mountain West.

José M. Capriles

José M. Capriles is an Associate Professor of Anthropology at Pennsylvania State University. He is an anthropological archaeologist specializing in environmental archaeology, human ecology, and zooarchaeology.

Shannon Mahan

Shannon Mahan is a research geologist, TRIGA Reactor System Administrator, and Acting Deputy Center Director for the United States Geological Survey.