Multiple Approaches to Formation Processes: The Pine Spring Site, Southwest Wyoming Robert L. Kelly, 1, * David A. Byers, 2 William Eckerle, 3 Paul Goldberg, 4 C. Vance Haynes, 5 R. Mark Larsen, 6 John Laughlin, 7 Jim I. Mead, 8 and Sage Wall 9 1 Department of Anthropology, University of Wyoming, Laramie, WY 82071 2 Department of Anthropology, University of Utah, Salt Lake City, UT 84112 3 Western GeoArch Research, P.O. Box 521124, Salt Lake City, UT 84152 4 Department of Archaeology, University of Boston, Boston, MA 02215-1406 5 Departments of Anthropology and Geosciences, University of Arizona, Tucson, AZ 85721 6 Department of Renewable Resources, University of Wyoming, Laramie, WY 82071 7 Department of Anthropology, University of Wyoming, Laramie, WY 82071 8 Department of Geology, Northern Arizona University, Flagstaff, AZ 86011 9 Alpine Archaeological Consultants, Inc., P.O. Box 2075, Montrose, CO 81402-2075 Excavations in 1964 at the Pine Spring site in southwest Wyoming concluded that the site con- tains three cultural occupation levels; the earliest allegedly dates to the terminal Pleistocene and is associated with megafauna. However, excavations in 1998 and 2000, and analysis of the stratigraphy, AMS dates, micromorphology, and artifact carbonate isotopes, along with debitage refitting, density, orientation, inclination, burning, and trample damage, could not replicate the 1964 findings. A hiatus in deposition accounts for the highest density of artifacts, and the three original occupations are palimpsests. There is no unequivocal association between evi- dence of human activity and megafaunal remains. © 2006 Wiley Periodicals, Inc. INTRODUCTION The Pine Spring site (48SW101) sits at 2329 m (7640 ft) on the north face of Black Mountain in southwest Wyoming (Figure 1). The site encompasses nearly the entire cultural sequence of the region and is an important reference site for southwest Wyoming prehistory (Thompson and Pastor, 1995). Excavated by Floyd Sharrock in 1963 and 1964, Pine Spring contains thousands of artifacts, mostly debitage, and the remains of Pleistocene horse, bison, and camel. Sharrock defined three major episodes of occupation, the earliest of which he dated to circa 10,000 yr B.P. (all dates herein are uncalibrated) and claimed it was associated with megafauna. In this article, we reassess the site’s evidence for the three occupations and the association between arti- Geoarchaeology: An International Journal, Vol. 21, No. 6, 615–638 (2006) © 2006 Wiley Periodicals, Inc. Published online in Wiley Interscience (www.interscience.wiley.com). DOI:10.1002/gea.20126 *Corresponding author; E-mail: rlkelly@uwyo.edu.