| Archaeological evidence suggests human occupation in Idaho dating back to the terminal
Pleistocene. Many prehistoric stone tools recovered from the region were crafted from obsidian.
The Snake River Plain contains over 100 known outcroppings of obsidian with 23 distinct
geochemical variations. By geochemically characterizing obsidian artifacts and lithic quarries in
the region via X-ray Fluorescence, the localities that people used to exploit these lithic raw
materials can be known.
This study incorporates artifact provenance data with GIS modeling of least-cost travel
paths to identify spatial patterns in the distribution of obsidian artifacts in relation to their origin.
A set of spatial analysis geoprocessing tools introduced in 2020 for ArcGIS Pro software is
paired with Tobler’s off-path hiking function to calculate time approximations for obsidian
procurement. Additionally, to facilitate future research, a geodatabase was created that contains
artifact provenance data for Idaho as well as the data generated from this study which will serve
as Idaho’s permanent digital database for geochemically sourced artifacts.
Results indicate there are two preferred obsidian sources, located in the eastern and
western regions of Idaho, and transported throughout the state. Bear Gulch (58%) and Timber
Butte (56%) obsidian showed the highest rate of transport followed by Big Southern Butte
(44%), Brown’s Bench (40%), Owyhee (40%), Malad (32%), Cannonball (30%), and Obsidian
Cliffs (26%). |