Open-air sites, especially those dated to the late Pleistocene and early Holocene periods, are notoriously difficult to find. Site formation and taphonomic processes challenge preservation, making identifying discrete activity areas and even site boundaries particularly challenging. In Diversity in Open-Air Site Structure across the Pleistocene/Holocene Boundary, Kristen A. Carlson and Leland C. Bement gather a group of investigators who meet these challenges. In the nine chapters, the authors present case studies analyzing a variety of open-air sites located in Europe and North America to demonstrate that with careful excavation and clever spatial analyses, open-air sites can offer valuable new information about past lifeways.

One of the strengths of this volume is that it offers a variety of methodical approaches to studying open-air sites. Neil N. Puckett and Kelly E. Graf's (Chapter 4) analysis of the multicomponent Owl Ridge site, Alaska, is a stellar example of the power of spatial statistics for discovering discrete activity areas, otherwise-unidentifiable features, and piecing together the spatial organization of behaviors with little more than a lithic assemblage. Using a combination of average nearest neighbor, Ripley's K, and K-means cluster analyses, the authors find that Owl Ridge was occupied by early Alaskans for unique reasons through time, demonstrating that although some sites may have been “persistent places” on the landscape, the past behaviors that formed them were dynamic. The Water Canyon site, in New Mexico, was also occupied repeatedly by foragers, and Robert Dello-Russo and colleagues (Chapter 6) use spatial analysis and a series of radiocarbon assays to tease apart the complicated stratigraphy. Bruce B. Huckell and colleagues (Chapter 7) plot artifact-density maps and variation in lithic material types when investigating the Folsom kill/camp site at Boca Negra Locus B, New Mexico. They demonstrate that even shallow, eolian contexts can preserve useful spatial patterning. Bement and colleagues (Chapter 8) use stable carbon isotope values, the number of hearths, lithic material type, and the presence of drying rack and/or wind break features to determine the season of occupation at the stratified Bull Creek camp and nearby Ravenscroft kill site in Oklahoma. They present compelling evidence of differences in camp organization as Paleoindian populations shifted from specialized bison hunting in the winter to generalist foraging in the summer.

Many of the case studies demonstrate that the discovery of hearths and domestic structures is critical for assessing the use of space, and readers will appreciate the variety of approaches used to document and compare these features. In an analysis of Paleolithic and Mesolithic sites in southwestern Germany, Michael A. Jochim (Chapter 2) considers how variation in the nature of hearths—from simply traces of charcoal scattered across a surface to oval basins lined with clay—may reflect differences in occupation duration and group size. Karisa Terry and colleagues (Chapter 3) investigate the organization of living spaces during the Early and Terminal Late Glacial occupations at the Studenoe site in Transbaikal, Siberia. They compare cobble-lined interior dwelling areas to exterior occupation areas and measure hearth spacing and fill depth to conclude that the organization of habitation space reflects a shift from extended family– to nuclear family–defined spaces. With good site preservation and rich datasets on their side, the authors engage in an insightful discussion of changes in group aggregation and dispersal throughout the Late Glacial. Not all sites have sedimentological indications of hearths. In an analysis of Block B at the La Prele Mammoth site in Wyoming, Madeline E. Mackie and colleagues (Chapter 5) turn to other convincing lines of evidence—such as the geometric centers of calcined bone and burned lithics—to define hearths and describe hearth-centered activities. In a review of spatial patterning at the Allen site in Nebraska, Douglas B. Bamforth (Chapter 9) argues that hearths may not always be focal centers of social activity; instead, they can be positioned on the periphery of camps, and in the case of Allen, associated with trash middens. Bamforth demonstrates that site maintenance—cleaning occupation floors and discarding large piles of lithic debris and animal bone—created dump features that are insightful residues of nearby activities.

Overall, this book is an enjoyable and informative read, rich with a variety of methods for open-air archaeology. Although the editors describe the admirable goal of refocusing away from large game kill sites, this was not necessarily the case throughout—many chapters describe carcass-centered activities. Still, the volume offers a refreshing take on those records, moving discussions beyond subsistence to consider broader aspects of hunter-gatherer social organization.