Systematic syntheses of data on flaked stone tools, the single-most universal category of archaeological material, are sadly rare these days. This volume would stand out in any era, however. It is a thoughtful, problem-oriented, data-rich synthesis of detailed information on flaked stone assemblages from the Missouri River valley in North and South Dakota (the “Middle Missouri”) dating from Paleoindian times to the colonial era. Johnson collected the data here (including information on raw material, tool and types, etc.) over decades of research on a related synthesis of Middle Missouri ceramics (Johnson, A Chronology of Middle Missouri Plains Village Sites, Smithsonian Institution, 2007), drawing heavily on approaches to lithic analysis pioneered by Stan Ahler. We can, and should, debate the interpretation of categories such as “used” flakes as well as distinctions between biface and other reduction debris, but relying on explicit standards for data gathering means that we can do that effectively.

The volume opens with discussions of Middle Missouri culture history, approaches to lithic analysis, and theoretical and conceptual issues of interest in this study. This last emphasizes optimization arguments derived from central place foraging theory along with considerations of exchange (especially in prestige goods). Johnson especially argues, sensibly, that people should eliminate more excess weight from transported material when they obtain stone at greater distances from their residences. He then turns to his analysis, presenting detailed site-by-site information on frequencies of tool classes by raw material and analyses of patterns and intensity of reduction. Appendices at the end describe the sites in Johnson's sample and present the data he uses.

Johnson's data derive overwhelmingly from horticulturalist towns occupied within the last 1,000 years. Nevertheless, he shows significant long-term patterns of continuity and change in use of different stone that reflect proximity to source areas as well as, in the last millennium, patterns of continuity and change in major social boundaries that altered access to exchange networks. Technological data generally confirm expectations about reduction patterns, modified somewhat by raw material characteristics and some other variables. Johnson understands that many factors condition how people made and used tools and his discussion takes that complexity into account. He also understands how incomplete our knowledge is, and he ends with recommendations for future research on such topics as acquiring more detailed information on specific raw material source locations, integrating information on other traded materials with information on toolstone, and generating more comprehensive data from experimental replication.

The volume focuses mainly on Plains Village data from the second millennium AD and it spends perhaps more time on culture-historical taxonomy than is necessary. This mirrors much of Plains Village archaeology in general, though, and Johnson often analyzes his data in terms of the culture-historical taxa he discusses. We need to remember, however, that these taxa are purely archaeological constructs that probably do not correspond to ancient social groups. The broadest of these generally mark a difference between Siouan speakers, labeled “Middle Missouri” (the Mandan and, in fairly recent times, the Hidatsa), and Caddoan speakers, labeled “Coalescent” (the ancestors of the Arikara and the Pawnee). Analysis at this level shows important regional patterns: aggregate raw material data leave no doubt that the fourteenth-century Caddoan movement into the Middle Missouri region profoundly changed the flow of goods through the regional exchange system. Analyzing the data this way, however, homogenizes the diverse ways that independent communities engaged in exchange and other activities in the past. But Johnson's thorough data presentation provides site-by-site/community-by-community information arrayed from upstream to downstream, allowing readers to assess geographic patterns easily. And he recognizes interesting site-specific deviations from overall aggregate patterns, including an apparent surplus of Knife River flint (present disproportionately as tools, not debris) at the Mitchell site in southeastern South Dakota, an important trade center that may have redistributed that material as part of a larger exchange network linked to Cahokia.

It is too easy to find studies in our field whose theoretical preferences shape the ways analysts choose and use evidence. Johnson does archaeology a great service by making his theoretical and conceptual expectations clear, acknowledging the complexity of the human processes he hopes to study and the limitations on what we know, offering clear and relevant analyses, and making his data available for others to expand and reconsider. We can debate, agree, and disagree with his specific arguments using his own data if and as we choose. Archaeologists should hope to do as well as he has, regardless of where they work and what they study.