THESIS SURFACE LITHIC SCATTERS IN THE CENTRAL ABSAROKAS OF WYOMING Submitted by Paul Burnett Department of Anthropology In partial fulfillment of the requirements for the degree of Master of Arts Colorado State University Summer 2005 ii ABSTRACT OF THESIS SURFACE LITHIC SCATTERS IN THE CENTRAL ABSAROKAS OF WYOMING This thesis provides baseline data on the variability of prehistoric lithic scatters documented across surfaces in the central Absaroka Range of northwestern Wyoming. Prehistoric hunter-gatherer behaviors and landscape attributes driving this variability are interpreted, and the dimensions controlling archaeological variability in this montane setting are defined. Themes of behavioral continuity and change are common to researching human systems, and in the Absaroka Range this research is especially relevant for anthropologists and earth scientists studying Holocene change. A total of 26,478 records of flaked stone data have been documented in situ within the montane watersheds of the Upper Greybull and Wood rivers, collectively referred to as the “Upper Greybull” for brevity. To describe the archaeological variability of these data, the periods of prehistoric human occupation are first defined. The method of lithic cross-dating is used on the projectile point sample (n = 224) to establish this sequence of prehistoric occupation. These artifacts were spread across 1050 km2, and variability in the abundances of projectile points is assumed to roughly reflect the intensity of occupation in the area. The results conform to other montane chronologies in the region, showing that the montane landscapes of the central Rocky Mountains were used maximally during the Late Archaic period (ca. 3000 - 1500 Radiocarbon Years Before Present [RCBP]), and that this land use was sustained but may have been slightly lower during the Late Prehistoric period (ca. 1500 – 250 RCBP). Land use earlier in the Holocene is evident, but it appears to have more than doubled during the Late Archaic. Artifact diversity associated with the diagnostic projectile points reflects some of the behavioral diversity of the hunter-gatherers that lived in this ecosystem. A GIS is used to create artifact clusters that are compared in terms of three variables: size (number of artifacts), toolstone variability, and artifact type variability. While small clusters are by far the most populous, assemblages of all sizes occur in all elevations of the Upper Greybull. Large high elevation clusters were produced at toolstone procurement iii workshops, whereas large clusters in the low and middle montane elevations were made during residential camping activities. To compare the variability in toolstone and artifact types in these assemblages, two indices are developed: the Toolstone Variability Index (TVI) and the Artifact Type Variability Index (AVI). These indices provide useful structure for the comparison of artifact assemblages not only in the Upper Greybull, but from any sample of assemblages with artifact type and toolstone data. Upper Greybull clusters exhibit a wide range of sizes and TVI and AVI values, but there is a tendency for clusters to have similar characteristics rather than each cluster being unique. This similarity reflects patterned settlement and subsistence behavior in response to topography and resource availability. Variability in cluster toolstone proportions are largely conditioned by proximity to source areas. The nearest obsidian sources are on the western side of the Greater Yellowstone Ecosystem (GYE), and its presence in the Upper Greybull on the eastern side of the GYE indicates that hunter-gatherer mobility patterns of the GYE included seasonally-patterned east-west intermontane travel in the course of a year. Most obsidian is associated with late Holocene time periods (post-3000 RCBP), indicating that patterned intermontane mobility regimes may not have been as common in the early Holocene as they were later. Cluster artifact type proportions vary widely across the Upper Greybull. Both typical and atypical artifact type proportions are found throughout the sampled space. In the lower elevations (below ca. 2800 masl), projectile points are atypically abundant. These are the product of retooling activities conducted at residential camps. Artifact type proportions are more variable in clusters not containing projectile points, and the majority of these clusters reflect task-specific non-residential activities. Changing projectile point abundance and obsidian content indicates that the intensity of hunter- gatherer land use involving intermontane travel across the GYE increased after 3000 RCBP, and perhaps as early as 5000 RCBP, but reasons for this increased travel are unclear. Although regional mobility appears to have changed through time, artifact type proportions remained relatively unchanging in the Upper Greybull. This reflects low diachronic variability in local hunter-gatherer behaviors through time, amidst changes in regional mobility patterns. The intensity of land use changed through time, but similar behaviors were employed when hunter-gatherers used the Upper Greybull landscape. This synthesis of iv surface lithic scatters in the Upper Greybull is proof that meaningful interpretations of prehistoric behavior can be drawn from an individual artifact-based approach to surface archaeological documentation. Paul Burnett Anthropology Department Colorado State University Fort Collins, CO 80523 Summer 2005 v ACKNOWLEDGEMENTS Colorado State University students that took the chance and enrolled in the 2002-2004 field classes in the Upper Greybull have my sincere thanks. They made the data collection enjoyable and provided memories that will last a lifetime. However, if I forget their names I can find them in Appendix A, Table A.3. Thanks to Sam Cason for helping me with the GIS clustering method. While I knew that I wanted to group artifacts into clusters using GIS, I didn’t know how to do it until he taught me how to create buffers and clip themes. The many years at CSU have been filled with interesting discourse among the processual types in my archaeological cohort. There is a great sense of community within this group. For some reason, archaeologists of my generation in Fort Collins like to play acoustic (and now electric) music, and some of the best times have been had while geeking-out on archaeology between songs at picking parties. For this and for being a part of it all, I’d like to thank Jeff and Jen Adams, Rich Carlsen, Cory and Sam Cason, Brian and Kimmy Coven, Bradford Lee Folk, Larry Fullencamp, Erik Gantt, Alisa Hjermstad, Julie Jones, John Kennedy, and Kelli Lackett, and Julie Risenhoover. While more grinners than pickers, the rest of the friends and fellow students that helped me develop as an archaeologist include Allison and Spike Bohn, Kelly Derr, Chris Kinneer, and Scott Slessman. Oskar Burger deserves special thanks for his continual advice, encouragement, and friendship. He is a foundation of our loose-knit group of budding landscape taphonomists, and I am indebted to him for his help in my archaeological development and for his useful suggestions on the thesis draft. Scott Slessman and Kevin Thompson of SWCA Environmental Consultants were happy to give me all the time I needed to complete this project and they continue to support my scientific interests in landscape archaeology. For this I am truly grateful. I will forever be indebted to my adviser, Dr. Lawrence Todd, for training me how to be an archaeologist. I gained my first real interest in archaeology when I took his class in Hunter-Gatherer Ecology as an undergraduate six years ago and enrolled in his class on his excavation at the Kaplan-Hoover Bison Bonebed that fall. I have been hooked ever since. He is a great teacher, and he and Becky Thomas vi are dear friends that have made this whole experience a blast. I am grateful that he and Drs. William Lauenroth and Matthew Hill agreed to be on my committee. They all happily donated their valuable time and provided much-needed guidance. I greatly appreciate the chance to work with Dr. David Rapson, who provided very useful advice during the early development of this project. Thanks also to the previous and current department heads, Drs. Jeffrey Eighmy and Kathy Galvin for supporting this project and providing beneficial discourse. Lastly, I would like to thank my family for their love, encouragement, and patience. My wife Kristy has graciously given me all the time and support that I needed to complete this project. Kristy has captivated me ever since I met her at that nerdy Honor’s retreat long ago. She has kindly taken care of our two sons, Hank and Buck, during my 10-day field work sessions and again while I sat in front of my computer at home for days on end. All of this while working a full-time job! For this I also thank her excellent and always flexible employers at Forcefield. She and our sons have given me the motivation to complete this project, and I look forward to spending more time with them. Thanks also to Kristy for the editing and for the extremely useful comments on the first draft. vii TABLE OF CONTENTS ABSTRACT OF THESIS .............................................................................................................................III ACKNOWLEDGEMENTS ......................................................................................................................... VI TABLE OF CONTENTS ...........................................................................................................................VIII