1. Museum of Natural and Cultural History, University of Oregon, Eugene, OR 97403, USA.
2. Department of Anthropology, University of Oregon, Eugene, OR 97403, USA.
3. Program in Human Ecology and Archaeobiology, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.
4. Department of Anthropology, Humboldt State University, Arcata, CA 97775, USA.
5. Department of Geography, San Francisco State University, San Francisco, CA 94132, USA.
6. Joint Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont, CA 91711, USA.
7. Department of Anthropology, Southern Methodist University, Dallas, TX 75275, USA.
8. Northwest Research Obsidian Studies Laboratory, Corvallis, OR 97330, USA.
9. Kellogg College, Oxford University, Oxford OX2 6PN, UK.