In federal Indian law, the treaty operates as our foundational legal text. Reflecting centuries-old historical political arrangements between Indian nations and the United States, treaties remain vital legal instruments that decide dozens of legal cases each year. Yet, these treaties — originally drafted in English by the federal government, following negotiations with tribal representatives who usually spoke their own languages — present a number of ambiguities for contemporary courts. The dominant model of treaty interpretation is one in which judges interpret treaties in a manner they they believe to reflect Indians’ understanding of treaty terms and, more generally, to promote the interests of Indian nations. While this liberal approach to treaty interpretation has secured a number of important Indian rights in the courts, it does not necessarily reflect the ways in which Indians actually perceived treaty terms in their own languages and cultures.