"Steve Shackley has continued, throughout his career, to bring source provenance studies of obsidians and other volcanics to a point of real relevance in research about both Paleoindian and archaic mobile hunter-gatherers, as well as about the formative-era farmer-foragers of New Mexico, Arizona, and beyond. The professional archaeological and geological communities owe Steve a great debt of gratitude for his generosity and determination in these endeavors, as they have helped expand our scientific understanding of prehistoric cultures in the wider American Southwest."—Tristan Carter, McMaster University"This is a terrific book, engagingly and accessibly written, yet underpinned by top-notch science, robust data, and years of experience. While focused on the North American Southwest, this text has much to inform those working in obsidian studies—and geoarchaeology more generally—worldwide."—Robert D. Dello-Russo, director emeritus of the UNM Office of Contract Archaeology