TRACKS EAST OF THE HOTSPOT: ARCHAEOLOGY OF ABSAROKA MOUNTAINS, GREATER YELLOWSTONE ECOSYSTEM

The path and current location of the Yellowstone Hotspot have set the stage for an array of recent and contemporary ecosystem dynamics including human land use patterns and ungulate migration pathways. Ken Pierce’s work on impacts of the hotspot on landscape formation, ecology, and human adaptations to the Greater Yellowstone Ecosystem (GYE) serves as an important starting point for examining the higher elevation archaeological record of the Absaroka Mountains in the southeastern GYE. Since 2002, the Greybull River Sustainable Landscape Ecology (GRSLE) project has been investigating archaeological evidence of long-term human use of the Absarokas as well as resources, such as obsidian, derived from both Yellowstone and further west along the hotspot track. Focusing on high elevation (>2500 m) archaeological inventory and on individual artifact data collection rather than site-based recording, over the last two decades GRSLE has completed systematic inventory of 3681 ha, documenting locational and descriptive data on over 220,000 artifacts ranging in age from Late Pleistocene to less than 200 years in age – Paleoindian spear points to glass trade beads. Of the over 2200 projectile points and point fragments recorded, 70 are designated Paleoindian (>8000 years), 1099 as Archaic (2000-8000 years), and 685 Late Prehistoric (<2000 years). The mean artifact density of 59.6 artifacts per hectare inventoried clearly indicates that although much of the area is currently designated Wilderness, Pre-Contact Indigenous peoples’ use of these mountain landscapes was much more intensive and integrated than often portrayed. While only 4.8% of the documented chipped stone pieces are obsidian (N=8825), of the geochemically sourced artifacts (N=1322) the majority (N=893; 67.5%) were humanly transported from Yellowstone Plateau sources (Obsidian Cliff, Lava Creek Tuff, and Park Point) that are over 110 km from the core GRSLE project area.

These data indicate a range of Pre-Contact land use in the eastern GYE and highlight how the Yellowstone Hotspot has shaped mountain landscapes that provide a distinct set of adaptive challenges and opportunities. The hotspot-influenced GYE archaeological record indicates a complex mix of travel corridors, stop-over/occupation areas, and diverse resource acquisition strategies.