Through the Mountains to the Sea: an Analysis of Champlain Sea Shorelines, Site Patterning, and Travel Corridors in the Eastern Champlain Basin, Vermont, U.S.A. Francis “Jess “ Robinson- University of Vermont Consulting Archaeology Program, Ph.D. Candidate, University at Albany-SUNY John G. Crock, Ph.D.- University of Vermont Wetherbee Dorshow, Ph.D.- University of New Mexico Introduction: The Champlain Sea formed near the end of the Pleistocene epoch as a result of the recession of glacial ice north of the Gulf of St. Lawrence. Following the greater Lake Vermont lood pulse through this outlet, the isostatically depressed land comprising much of the St. Lawrence lowland, the Champlain Basin and portions of Ontario became inundated by North Atlantic marine waters. Geologists irst recognized the Champlain Sea event over a century ago (e.g. Woodworth 1905), motivated in part by the discovery of whale skeletons and other marine fauna at various regional inland locales (e.g. Thompson 1850). However, dating the inception, tenure, and eventual drainage of the Champlain Sea event has historically been quite problematic for regional researchers. Within the past decade, a relatively large amount of research has begun to rectify the formerly contradictory evidence regarding the marine geochronology of the region (e.g. Cronin et al. 2008; Rayburn et al. 2007). This revised chronology has important implications for the occupation of the Northeastern region by Paleoindians. Middle and Late Paleoindian projectile points from the Reagen site, East Highgate, Vermont (Ritchie 1953); Robinson 2008, 2009, 2010). A portion of a map reproduced from Ritchie’s Traces of Early Man in the Northeast (Ritchie 1957: Figure 2). The bold black line indicates the limits of the Champlain Sea as mapped in 1957. Ritchie plotted the locations of known Paleoindian sites and spot inds as a way to generate an indirect dating mechansim for them. History of Research: A direct connection between Paleoindians and the Champlain Sea was irst formally proposed by William Ritchie during his initial investigations of the Reagen site and other regional Paleoindian sites in the early and mid-1950s (Ritchie 1953, 1957). Ritchie’s primary interest seemed to lie in the potential for an indirect dating mechanism for the Paleoindian occupations of the Northeast. This technique had been employed by several of Ritchie’s contemporaries in the Great Lakes region ( e.g. Mason 1958, 1960; Quimby 1958, 1959), and seemed to provide evidence of an antiquity for the Paleoindian occupations in that area commensurate with the more famous sites in the West and High Plains (e.g. Wormington 1957). Unfortunately, the geological radiocarbon dates that Ritchie referenced for the Champlain Sea were too recent to it comfortably within the Paleoindian period as it is generally understood today, and as it was coming to be understood then. Instead of questioning the dates, however, Ritchie initially proposed a delayed and extended Paleoindian occupation in the far Northeastern region. This theory was soon contested by other researchers (e.g. Mason 1960). Vermont Paleoindian projectile points exhibiting the morphological differences characterizing the sub-divisions of the Paleoindian period as deined by Bradley et al. (2008). From left to right: Bull Brook/West Athens Hill point from the Mahan site (VT-CH-197), Williston; Michaud/Neponset point from the Fairfax Sandblow site (VT-FR-64); Crowield-related point from Bristol Pond (VT-AD-11); Cormier-Nicholas point from the Reagen site (VT-FR-3); St. Anne/Varney point from Colchester, Vermont, Gonyeau Collection. In 1980, Loring readressed the issue when he published an article in Man and the Northeast entitled, “Paleo-Indian Hunters and the Champlain Sea: A Presumed Association”. The article, in part, plotted a number of luted point isolates with (variably reliable) provenience information over a map of the maximum margins of the Champlain Sea. From the resulting synthesis, Loring promulgated the theory that there was a direct correlation between the margins of the Champlain Sea and Paleoindian groups.Unfortunately, like Ritchie before him, the dates of the Champlain Sea at the time of Loring’s writing did not agree with the generally accepted date ranges for Paleoindians in the region. At that time, however, the dates assigned to the Champlain Sea event were seen as being too old for Paleoindians, not too young. A revised chronology of the inception and tenure of the Champlain Sea (e.g. Cronin et al. 2008; Rayburn et al. 2007), coupled with a recently-developed Paleoindian biface sub-chronology for the the Far Northeastern region (Bradley et al. 2008), offered data sets suficient to reexamine the possibility that Paleoindian occupations in the Champlain Basin were coeval with the Champlain Sea. These data generate research questions related to how this major hydrological entity structured Paleoindian lifeways. In order to conduct this analysis, an updated model of the Champlain Sea was generated in ESRI’s ArcMap (10.1) program using elevational and suricial geological data. After consultation with geologist colleagues, it was determined that the Champlain Sea maximum is the only shoreline feature that can be adaquately mapped, due to the pronounced incision of these features at its initial inundation. Known Paleoindian sites and spot inds (many of which were documented during regulatory surveys by the UVM Consulting Archaeology Program) were analyzed, renanalyzed, or documented for the irst time in order to derive accurate site information and locations for mapping (Crock and Robinson 2012; Robinson.2009, 2012; Robinson and Crock 2008). The locations were then plotted relative to the Champlain Sea shoreline at its maximum, and broken down into sub-periods on the basis of distinctive projectile point morphologies (no radiocarbon dates are available for Paleoindian sites in Vermont). The results are briely illustrated in the maps to the right. Map 1. The eastern Champlain Basin with the Champlain Sea maximum and Bull-Brook/West Athens Hill (ca. 12,700- 12,200 cal yr B.P.) sites indicated by black triangles (Underlying hillshade and DEM layers downloaded from the Vermont Center for Geographic Information, 2011). Map depicting the approximate limits of the Atlantic shoreline and the Champlain Sea (center-left) in the Far Northeast, ca. 11,700 cal yr B.P. The southernmost arm of the Champlain Sea extended into the Champlain Basin, which currently spans a portion of the New York (west)/Vermont (east) boundary (physical basemap downloaded from esrionline.com 2011). Figures clockwise from upper-left: close-up view of three Bull-Brook/West Athens Hill sites (including Mahan [VT-CH-197]) relative to the Champlain Sea Maximum and the Winooski River outlet (underlying hillshade and LIDAR data sets downloaded from the Vermont Center for Georgraphic Information, 2011); Bifaces in various stages of reduction from the Mahan site (VT-CH-197); Michaud/ Neponset projectile points from the Fairfax Sandblows site (VT-CH-64) (materials include probable Munsungan chert and Mt. Jasper Rhyolite); various unifaces from the Mahan site (VT-CH-197) (materials include Munsungan chert, Mt. Jasper Rhyolite, Hudson Valley chert and Pennsylvania Jasper). Map 2. The eastern Champlain Basin with the Champlain Sea maximum and Michaud/Neponset (ca. 12,200-11,800 cal yr B.P.) sites indicated by black triangles (Underlying hillshade and DEM layers downloaded from the Vermont Center for Geographic Information, 2011). Map 3. The eastern Champlain Basin with the Champlain Sea maximum and Crowield-related (ca. 11,800-11,500 cal yr B.P. [general]) sites indicated by black triangles (Underlying hillshade and DEM layers downloaded from the Vermont Center for Geographic Information, 2011). Map 4. The eastern Champlain Basin with the Champlain Sea maximum and Cormier/Nicholas (ca. 11,500-10,800 cal yr B.P.) sites indicated by black triangles (Underlying hillshade and DEM layers downloaded from the Vermont Center for Geographic Information, 2011). Map 5. The eastern Champlain Basin with the Champlain Sea maximum and St. Anne/Varney (ca. 10,800-10,000 cal yr B.P. [general]) sites indicated by black triangles (Underlying hillshade and DEM layers downloaded from the Vermont Center for Geographic Information, 2011). Paleoindian Settlement and the Champlain Sea: During the Bull Brook/ West Athens Hill portion of the Early Paleoindian period (ca. 12,700-12,450 cal yr B.P.), which thus far represents the earliest period of occupation in the Champlain Basin, there is a notable concentration of three sites around the area where the Winooski River emptied into the Champlain Sea (Map 1 and adjacent map). During the subsequent Middle Paleoindian period (ca. 12,200-11,800 cal yr BP), deined by the production of Michaud/Neponset projectile points, sites appear to be more widely distributed (Map 2). The uplands near Little Otter Creek and Bristol pond appear to become attractive locales. Perhaps most notably, the Fairfax Sandblows site (VT-FR-64), which apparently represents a fairly large Michaud/Neponset occupation (Robinson and Crock 2008), plots near to the area where the Lamoille River lowed into the Champlain Sea, depending upon the effects of isostatic rebound and sea regression during that time and the location information, which is approximate. By the subsequent Crowield-related Middle Paleoindian sub-period (ca. 11,800-11,500 cal yr B.P.), the Reagen site, near the mouth of the Missisquoi River, begins to be occupied (Map 3). It is likely that it was located somewhere near to the Champlain Sea during this period, although the lack of dates for Crowield sub-period sites and the vagaries surrounding the effects of isostatic rebound make mapping its precise location relative to the Sea speculative. Prior to the late portion of the the Middle Paleoindian period (11,500-10,800 cal yr B.P.) deined characterzied as the Cormier/Nicholas sub-period, none of the sites included in this data set signiicantly encroach upon the maximum limits of the Champlain Sea. Beginning during the Cormier/Nicholas sub-period [Map 4], however, this changes rather dramatically. Most notably, by tthe Late Paleoindian period (ca. 10,800-10,000 cal yr B.P.) [Map 5], the Champlain Sea appears to have receded well west of its maximum extent, as several St. Anne/ Varney sites plot very close to the modern Lake Champlain shoreline, excluding the major river deltas. Although the Reagan site exhibits projectile points attributable this sub-period, it appears that it was no longer in the immediate or even general proximity of the Champlain Sea. Although the data set is small, the diachronic distribution of Paleoindian sites demonstrates what appears to be a clear correlation between settlement and the Champlain Sea. First, there are no obvious anomalies plotted, such as a site signiicantly west of the Champlain Sea maximum during a period when that would not be expected. More interestingly, revised mapping of the inundation of the major river valleys along the eastern edge of the Champlain Basin, coupled with new and/or better plotting of sites, appears to demonstrate a correlation between sites and features that may have been estuaries, or places where rivers met the Champlain Sea. Furthermore, over time these data suggest that human settlement maps closely with receding Champlain Sea shorelines. While this research must be followed up by additional surveys of Champlain Sea shorelines, the biotic productivity of the Champlain Sea has been demonstrated at a general level, and accepting its contemporenity with the Paleoindian period, it can be presumed that marine resources were exploited by Paleoindians. Marine and associated avian resources in the Champlain Basn may have been more reliable than has been suggested for the Atlantic Coast, where the resource base has been shown to be more dynamic and unstable at the end of the Pleistocene. Finally, as a practical concern, whether exploitation of marine resources occurred in the Champlain Basin, along the Atlantic coast, or at both places on a seasonal or some other periodic basis, due to the inundation of the Atlantic Coast area by rising sea waters, the only evidence of it in the region, if it exists, will be identiied in the Champlain Basin or in adjacent regions of Québec, at least in the short to medium term. Results of Least-Cost Path Analyses: Most regional Paleoindian research has largely neglected the Champlain Sea in colonization models, subsistence patterns, movement trajectories, optimal foraging quantiications, or other related schema. This notable lacuna suggests that there needs to be a profound reworking of all of these models, and that many assumptions about Paleoindians in the Northeast generally may need to be reassessed. After demonstrating the close association of Paleoindian sites and the Champlain Sea shoreline and identifying Paleoindian period sites such as Jackson Gore (331 m a.m.s.l.) at higher elevations in the mountains to the east, we looked at potential east-west travel corridors through the Green Mountains as a irst step in understanding how Paleoindian groups might have accessed the Champlain Sea within this geographically circumscribed locale We conducted a least-cost path analysis from the outlets of major rivers into the Sea on the eastern side of the basin, through the Green Mountains, to the Connecticut River Valley farther to the east. A cost surface was created using a 10 m resolution elevation model. We generated a percent slope raster that was subsequently reclassiied into six ordinal classes: 0-10% = 1; 10-20% = 2; 20-30% =3; 30-40%= 4; 40-50% = 5; 50-60% = 5; > 60%= restricted (impassable). The analysis identiied least-cost pathways largely correlated with major river valleys, many of which also contain recorded Paleoindian sites. The analysis illustrates the movement of people between the Sea and its resource potential, and resource areas in or passageways through the mountains. These results, along with the locations of sites, indicate the limitations of traditional south-north transhumance models. To further investigate the role of the Champlain Sea in organizing the movement of people and materials during the Paleoindian period, we explored the relationship Paleoindian period sites in and near the Champlain Valley and the source areas for lithic materials recovered at these sites. To do this, we conducted a least-cost path analysis that assumes direct acquisition and direct travel between sites and individual sources. The analysis began with the creation of a multi-criteria cost surface designed as a proxy for relative travel dificulty. The cost surface was created from two primary landscape factors: slope and land cover. Using a 90 m resolution elevation surface (based on the SRTM dem [CSI 2013]), we generated a percent slope raster that was subsequently reclassiied into six ordinal classes: 0-10%, cost score = 1; 10-20% = 2; 20-30% =4; 30-40%= 6; 40-50%; 50-60% = 10; > 60% = restricted (impassable). Using the weighted sum function, slope was assigned twice the weight of the land cover criteria. This allowed us to prioritize slope as the most driving factor governing least-cost travel. The slope cost surface was combined with the land cover cost surface in a weighted overlay. The land cover raster was based on two hydrologic categories: the projected extent of the Champlain Sea and, to highlight major, partially navigable river corridors, all river reaches with upstream drainage areas of at least 4,050 hectares (based on the SRTM dem [CSI 2013]). Areas within the projected Sea boundary were assigned a relative cost score of 2, on a scale of relative dificulty from 1 to 10, where 1 is considered least dificult. A score of 2 was chosen to model the relative ease of travel by watercraft on the Sea. To model River travel, major river center lines were buffered by 200 m to generate approximate corridors with potentially navigable waterways. We assigned relative cost surface scores of 1 to the major river corridors to model the ease of travel by watercraft (slightly easier than on the Sea). For the purposes of analysis, we assumed that all areas not covered by water were likely forested and these forested areas were assigned a score of 8, again to highlight the potential importance of travel by watercraft and the relative dificulty of travel along smaller drainages or overland. The combined weighted cost surface was then used as input to a series of path distance and corridor analysis functions to look at paths between sites and lithic sources. The routes identiied illustrate the importance of the Champlain Sea as a travel corridor and also point to travel cost as an explanation for why some sites and some sources are so closely linked, such as the Fairfax Sandblows site and Mt Jasper rhyolite, or the Mahan Site and Munsungan chert. The potential route from the St Lawrence river portion of the Champlain Sea into northern Maine and Munsungan Lake is particularly compelling and may indicate that the Champlain Sea was a major factor in making this material more accessible to Paleoindians and may help explain why this material appears so early in the archaeological record in Vermont. Acknowledgements: The New York (western Champlain Basin) Champlain Sea shoreline data and a portion of the eastern Canadian Champlain Sea shoreline data used in the least-cost path analyses were provided by David A. Franzi, Ph.D. (SUNY-Plattsburgh) and John Rayburn, Ph.D. (SUNY-New Paltz). We thank them very much for their generosity and with their assistance in our interpretations of the Champlain Sea event.The late James B. Petersen is also greatly thanked for aggregating together most of the extant Reagen collection before his passing, and for inspiring us to pursue Paleoindian and Paleoindian-related research. We would also like to greatfully acknowledge the following people and institutions that have inspired, aided, or helped to faciliate this research: Earl Bessette, Jim Bradley, Hetty Jo Brumbach, Adrian Burke, Claude Chapdelaine, R. Scott Dillon, Earth Analytic, Inc., William Haviland, Jon Lothrop, Geoffrey Mandel, Giovanna Peebles, Art Spiess, Peter Thomas, and The University of Vermont Consulting Archaeology Program’s staff, past and present. References: Bradley, James W.. Arthur E. Spiess, Richard Boisvert and Jeff Boudreau 2008 What’s the Point?: Modal Forms and Attributes of Paleoindian Bifaces in the New England-Maritimes Region. Archaeology of Eastern North America 36:119-172. Consortium For Spatial Information 2013 http://www.cgiar-csi.org/data/srtm-90m-digital-elevation-database-v4-1 Crock, John G., and Francis W. Robinson IV 2012 Maritime Mountaineers: Paleoindian Settlement Patterns on the West Coast of New England. In Late Pleistocene Archaeology and Ecology in the Far Northeast, edited by Claude Chapdelaine, pp. 48-76. Peopling of the Americans Publications, Michael R. Waters and Ted Goebel, general editor. Texas A&M University Press, College Station. Cronin, T.M., P.L. Manley, S. Brachield, T.O. Manley, D.A. Willard, J.-P. Guilbault, J.A. Rayburn, R. Thunell, and M. Berke 2008 Impacts of Post-Glacial Lake Drainage Events and Revised Chronology of the Champlain Sea Episode 13-9 ka. Palaeogeography, Palaeoclimatology, Palaeoecology 262:46-60. Loring, Stephen 1980 Paleo-Indian Hunters and the Champlain Sea: A Presumed Association. Man in the Northeast 19:15-42. Mason, Ronald J. 1958 Late Pleistocene Geochronology and the Paleo-Indian Penetration into the Lowe Michigan Peninsula. University of Michigan, Museum of Anthropology Anthropological Papers 11. 1960 Early Man and the Age of the Champlain Sea. Journal of Geology 68(4):366-376. Quimby, George I. 1958 Fluted Points and Geochronology of the Lake Michigan Basin. American Antiquity 23(3):247-254. 1959 Lanceolate Points and Fossil Beaches in the Upper Great Lakes. American Antiquity 24(4):424-426. Rayburn, John A., David A. Franzi and Peter L. K. Kneupher 2007 Evidence from the Lake Champlain Valley for a Later Onset of the Champlain Sea and Implications for Late Glacial Meltwater Routing to the North Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology 246:62-74. Ritchie, William A. 1953 A Probable Paleoindian Site in Vermont. American Antiquity 18:249-258. 1957 Traces of Early Man in the Northeast. Bulletin No. 358. New York State Museum and Science Service. Robinson IV, Francis “Jess” 2008 The Reagan Site: A Reanalysis, Recontextualization, and Reappraisal of a Formative Northeastern Paleoindian Site, Anthropology, University at Albany- SUNY, MA thesis, Albany. 2009 The Reagen Site Revisited: A Contemporary Analysis of a Formative Northeastern Paleoindian Site. Archaeology of Eastern North America 37:85-147. 2010 A Brief History of the Reagen Site since its Discovery. Journal of Vermont Archaeology 11:1-14. 2012 Between the Mountains and the Sea: an Exploration of the Champlain Sea and Paleoindian Land Use in the Champlain Basin. In Late Pleistocene Archaeology and Ecology in the far Northeast, edited by Claude Chapdelaine, pp. 191-217. Texas A&M University Press, College Station. Robinson IV, Francis “Jess”, and John G. Crock 2008 The Fairfax Sanblows site: New Evidence about a Michaud/Neponset Paleoindian site in the Champlain Basin. The Journal of Vermont Archaeology 9:13-28. Thompson, Zadock 1850 An Account of some Fossil Bones found in Vermont, in making excavations for the Rutland and Burlington Railroad. American Journal of Science:256-263. Woodworth, Jay B. 1905 Ancient Water Levels of the Champlain and Hudson Valleys. New York State Museum Bulletin 84, Geology 8. New York State Education Department, Albany. Wormington, H.M. 1957 Ancient Man in North America. Popular Series, No. 4. Denver Museum of Natural History, Denver. Region, sites and lithic sources overlayed on the weighted cost surface showing least-cost corridors. Weighted cost surface with least-cost pathways between the Reagen, Mahan, and Jackson-Gore sites to the West Athens Hill chert source. All of the analyzed sites contain some amount of Hudson Valley chert. The West Athens Hill quarry is used as a single node for the purposes of analysis, but the pathway depicted here generally comports with travel from the sites to most of the major quarries within the general area of West Athens Hill. The easiest path is clearly via the Champlain Sea, Lake George, Hudson River system. To investigate east-west travel between the Champlain Sea and the Connecticut River Valley, we generated least cost surfaces using slope data to model potential routes through the Green Mountains An overlay of recorded Paleoindian sites shows the correlation between sites, the Champlain Sea shoreline, the outlets of major rivers and those river valleys into uplands to the east. The Middle Paleoindian Jackson Gore site, located at an elevation of 331 m a.m.s.l. is situated on a very low cost pathway between the Champlain Sea and the Connecticut River Valley, providing evidence of east-west travel and conirming assumptions that travel occurred along low cost paths through valleys. Region, sites and lithic sources included in least-coat path analyses. Note major rivers selected for their potential as potentially navigable waterways. Modiied least-cost path analysis from the Mahan site to the Munsungan Lake chert source. The Mahan site contains a signiicant amount of Munsungan chert. Various routes to and from the source are indicated, but the route of least cost was determined to be via the Champlain Sea northward and then through interior river systems to the source area. Weighted cost surface with least-cost path between the Fairfax Sandblows site and the Mt. Jasper rhyolite source. Artifacts recovered from the Fairfax Sandblows site include specimens made from Mt. Jasper rhyolite (Robinson and Crock 2008). Two major routes to the source are indicated, with one strongly determined to be the route of least cost. Michaud/Neponet Point made from Munsungan chert from site VT-AD-82. Illustration of the partially reconstructed Beluga whale skull recovered from marine clay beds in Charlotte, Vermont. Illustration reproduced from Thmpson (1850). Weighted cost surface with least-cost path between the Mazza site and the Mt. Jasper rhyolite source. The Mazza contains a signiicant amount of Mt. Jasper rhyolite (approximately 59% in terms of number of specimens) (Crock and Robinson 2012). A single pathway of least cost is indicated (compare with the igure to the left).