Acknowledgements go first to the people of the Colca valley who have kindly welcomed the foreigners who hike through their lands and camp on the volcanoes that ring the valley. I would like to acknowledge the support of my dissertation committee, Mark Aldenderfer, Katharina Schreiber, Michael Jochim, and Keith Clarke, who provided valuable guidance in this process. I am particularly grateful to my advisor Mark Aldenderfer who shares my fondness for mountain environments and the people who thrive there. My background was primarily in geography when Mark admitted me to the program at UCSB, and I am grateful that he recognized the contribution that a geographical emphasis can make to anthropological research. I would like to thank Katharina Schreiber who has terrific enthusiasm for the Andes and for prehistory, Michael Jochim has been willing to provide guidance and feedback at crucial moments during this research, and Keith Clarke whose knowledge of geography and enthusiasm for mobile geographical technologies were inspiring. Although not on my committee, Charles Stanish has been consistently encouraging and has provided valuable insights and a useful regional perspective.

This dissertation research was made possible by a doctoral dissertation improvement grant from the Nation Science Foundation and a UCSB graduate division dissertation fellowship. The fieldwork was conducted with a permit from the Instituto Nacional de Cultura - Perú. The UC Santa Barbara Anthropology Department and Letters and Science Information Technology, and the GIS division at URS Corporation/Santa Barbara have provided me with part-time work and have kindly put up with my odd schedule during this writing up process.

The Titicaca Basin is an excellent introduction to the Andes as it possesses enduring Andean cultural traditions, rich archaeology, and a collegial community of archaeologists that work there. My thanks to the many colleagues who have shared their insights and their data from the Titicaca Basin research, and to Cecilia Chávez and Edmundo de la Vega at the Puno house. Ever supportive, Karen Doehner contributed valuable advice and generously translated key documents. This research project is regional in scope and it inevitably has resulted in debts of gratitude to many people whose data and observations have contributed to this exploration of Chivay obsidian and regional interaction.

Striking out from the Titicaca Basin to work in Arequipa was made easier by the warm community and valuable facilities that I found there. The Centro de Investigaciones Arqueológicas de Arequipa (CIARQ) was a important base for field operations and a hospitable environment for lab analysis, and special thanks go to Karen Wise and Augusto Cardona for establishing and continuing this valuable facility. I am especially grateful for Augusto’s logistical support for this project, his enthusiasm and expertise in Arequipa archaeology, and for his hosting of memorable ceviche parties at CIARQ. The INC offices in Arequipa, in particular Marco Lopez, Cecilia Quequesana, and Lucy Linares, helped to make the bureaucratic hurdles less difficult.

This project was made possible by the energetic participation of a committed team of researchers and students from many countries. The enthusiasm of co-director Willy Yépez Alvarez made fieldwork at the high altitude source a pleasure, and made subsequent lab work in Arequipa and coordination with the INC proceed smoothly. Important contributions to the field research were made by Cheyla Samuelson and Alex Mackay who generously contributed months, even years, away from their own research goals to greatly advance this project and the data that has resulted from it. The theoretical and methodological merit of the lithics analysis in this project is largely due to Alex Mackay’s keen field observations, efficient lab procedures, and unparalleled speed with the digital calipers. Saul Morales has been a valuable friend and collaborator nearly every year since I first met him in Juli, Peru eight years ago. As Saul anticipated in 1999, he was an important contributor to this field project, and he was also an astute cultural mediator who relies sometimes on the axiom “ en Perú, todo es posible”. A sincere thank you is also due to all of the other tireless participants of the Upper Colca project, a list that includes Ross Burley, Mirza del Castillo, Erik Erwin, Brian Finucane, Guillermo Flores, Tamara Flores Ramos, Melissa Joubert, Chris Lagen, Adan Lacunza, José Ubeda, and Daniel Zimbler.

A great deal of credit for turning this geographer into an anthropologist goes to my colleagues at UCSB, in particular Elizabeth Klarich and Nathan Craig. I would like to thank Liz Klarich for her friendship and because her explanations of theoretical and regional subjects have been invaluable. Liz has been a reliable source of sound advice about grad school since I first visited Santa Barbara through to consultation about organizing this dissertation. Nathan Craig is a never-ending source of ideas for original ways to apply GIS to anthropological problems, for training in meticulous excavation work, and for demonstrating how tough and focused work in the field can be enjoyable.

I would like to thank Cynthia Herhahn for demonstrating how to supervise a project and for field training when I worked for her in Juli, my first year in Peru. Thanks also to Cynthia for joining us in 2003 in the Colca for a three day high altitude survey/backpacking death march, and thanks for follow-up discussions of my research as I wrote up this work. I am grateful also to Cindy Klink who provided advice and shared results from her work in the Ilave and Huenque valleys. Justin Jennings has been a good colleague as he has shared material from his work in Cotahuasi as well as valuable insights about working in the Arequipa. I would like to thank Steve Wernke for his friendship and collegiality, and for his advice about research and the community in the Colca valley. Other colleagues that have provided advice and encouragement include Matthew Bandy, David Browman, Michele Buzon, Augusto Cardona, Christi Conlee, José-Antonio Chávez, Miriam Doutriaux, Tobias Fischer, Sarah Fowler, Anabel Ford, Martín Giesso, Michael Glassow, Paul Goldstein, Ian Lindsay, Michael Malpass, Daniel Sandweiss, Ericka Simborth, Bruce Owen, Felix Palacios, Kurt Rademaker, Frank Spera, Waldo Tobler, Tiffiny Tung, Hendrik Van Gijseghem, Kevin Vaughn, and Ryan Williams. In the Colca valley, Timoteo and Adriana Valdivia, Eliseo Vilcahuaman Panibra, la Familia Espinel, la Familia Sotormayor, Saturnino Ordóñez, and Padre Franz Windischhofer all contributed in important ways to the success of this project.

Acknowledgement is due as well to the efforts of Richard Burger and Sarah Brooks and their collaborators in geochemistry for locating and first documenting the obsidian deposits in the Colca valley. Both researchers provided me with useful advice in carrying out this project. Michael Glascock at M.U.R.R. and M. Steven Shackley at UC Berkeley have both been generous with their time in educating me about geochemical analysis, and in analyzing obsidian source samples from Peru. Spatial data and imagery that were essential to this work was acquired from several agencies free-of-cost, and thanks are due to NASA, USGS, NIMA, Digital Perú, DigitalGlobe (GoogleEarth), and the IGS base station in Arequipa for GPS correction. Mark Aldenderfer was generous with equipment and I wish to thank him for the loan of GPS equipment and cameras for several seasons in a row, as well as for his truck that served as our field vehicle.

Finally, I would like to thank my parents, Robert Tripp and Susan Ervin-Tripp, for their interest, encouragement, and support through all stages of my research. My brother Alexander and sister Katya were likewise supportive. I would like to acknowledge the kind advice and direction from Laura Nader, family friend, and advocate for an integrative view of anthropology. My deepest love and gratitude goes to my wife Cheyla Samuelson who has contributed emotional support, encouragement, and effort to advancing my Ph.D. project from the beginning. She enthusiastically participated in the rigorous 5000m portion of the research, and her keen intellect and constructive observations helped considerably in directing this project. Cheyla spotted more than her share of projectile points during survey, and thanks to her concern for the crew while camping at the obsidian source we can say that “no students were permanently damaged in the making of this dissertation”!