The 1783 “Crawford Purchase” of Michi Saagiig (Mississauga) Anishinaabe lands at the northeast end of Lake Ontario is generally recognized as the first treaty in Upper Canada for purposes of settlement. Lacking deed, map, or signed treaty, it fails to meet the Crown’s own requirements for validity. More importantly, central elements do not match Michi Saagiig interests or understandings. Nineteenth-century testimony by Michi Saagiig leaders reveals a consistent claim to islands and other key shoreline spaces. These spaces had, and have, many dimensions of value, and Michi Saagiig claim to them demonstrates and enables the ongoing resilience of Michi Saagiig memory practices, political structures, and ecological relationships.