Located in the Cootes Paradise embayment at the westernmost end of Lake Ontario, Rat Island was first recorded as an archaeological site by David Stothers in the 1960s. Stothers noted a rich and homogenous Princess Point component concentrated on the island’s south-eastern end. His initial field notes, based on survey and test excavation, delineated a habitation area and two middens. These initial notes also suggested that the site was unplowed and thus represented one of the few undisturbed sites in the archaeologically rich embayment. For nearly forty years, this narrative remained unchallenged, contributing to our understanding of Rat Island and the larger Princess Point cultural complex. Subsequent follow-up investigations have altered our interpretations. Limited excavations by Scott Martin in 2001-2004 found evidence for a second Middle Woodland component but maintained much of Stothers’ narrative. Returning in 2018, we were drawn to Rat Island’s potential for observable settlement patterning and distinguishable cultural components. Applying soil chemistry, we were forced to challenge the longstanding interpretation of this place suggesting a much more recent disturbance associated with the 1837 construction of the Desjardins Canal. Our study underscores the utility of revisiting archaeological sites and the role of strong analytical data in their interpretation.