ABSTRACT Identifying ancient patterns of trade, exchange, and social relations through the tracking of the origin point and final place of deposition of objects is an integral part of archaeological research. Using such information, scholars have constructed elaborate interpretive models to explain the interactions of past societies. The key to success is the correct identification of the original material. In this project, we have undertaken the sourcing of the pipestones utilized by native people living in the Mississippian era in the region between Greater Cahokia and Aztalan in southern Wisconsin to make ear spools. For this research we employed near-infrared spectroscopy, x-ray florescence, and color measurement technology. Our research revealed that the primary source for regional Mississippian ear spools were two distinct variants of Baraboo pipestone from quarries in west-central Wisconsin. The analysis of the Aztalan ear spools and the recent discovery of an ear spool workshop area at the East St. Louis Mound Precinct have expanded our understanding of regional pipestone ear spool manufacture, distribution, and context. Our findings suggest that while Aztalan was enmeshed in a regional network of Baraboo pipestone exchange, Cahokia employed practices that focused on selective targeting for the acquisition of distant exotics.