During the Late Woodland Period in the American Southeast, the amount of space that any individual group could exploit began to shrink, due to the presence of other groups on the landscape. Resource expansion occurred to augment food supplies, resulting in increased exploitation of mussel beds. Because mussels can be extremely sensitive to the characteristics of the waterways they live in, the specific habitat requirements of these animals can be used to reconstruct the environments they were recovered from. In this thesis I use freshwater mussel assemblages to reconstruct hypothetical aquatic catchments and map them onto modern rivers in the Yazoo River Basin and the Tombigbee River Basin. These are used to test ethnographic models of exploited space. I also use detrended correspondence analysis to test if sites exist in mathematical space like they do in physical space along the Yazoo River basin, as observed in the Tombigbee River basin.