Abstract: Humans experience climate effects on scales that directly affect the availability of key subsistence resources, such as the location and abundance of fish populations. This is especially true for those populations that reside near and depend upon estuarine ecosystems where sea level change and/or changes in salinity can act as primary driving forces in the distribution and configuration of these ecosystems. Thus, utilization of past large scale global climate trends is at an insufficient resolution to understand the relationship between local ecologies and human behavior in the past. The research presented here explores the consequences of environmental change on economic strategies that in turn influence past Indigenous North American sociopolitical and socioeconomic organization. This talk will explore several archaeological regions in the US Southeast, specifically southwestern Florida and the Georgia Coast, and will provide some examples of how archaeologists are addressing past human-climate dynamics using a combination of high-resolution Bayesian chronological modeling of radiocarbon dates, oxygen isotope geochemistry of incremental marine shell growth bands, oyster paleobiology, and zooarchaeological analysis of vertebrate and invertebrate refuse.