White and colleagues (2020) have argued that after Cahokia's AD 1400 decline, the native population in the Horseshoe Lake Watershed rebounded beginning in AD 1500 and peaked around 1650, and that the native groups populating the area were members of the Illinois Confederation. These arguments are based on a population reconstruction obtained from fecal stanol concentrations from Horseshoe Lake sediment cores and regional historical, archaeological, and environmental data. We argue that their interpretations are problematic because they discount extensive regional archaeological and historical datasets and do not consider alternative hypotheses that could explain high levels of fecal stanol concentrations in lake sediments.