The study focuses on a two-week unit with 90 students at an urban, Latinx-serving charter middle and high school in the south midwestern U.S. to create digital counterstory maps. The maps then served as the organizing content for a subsequent week-long summer professional development the authors led for their teachers. Analysis suggests the significance of engaging the students' counterstories and cultural knowledge for designing teacher education committed to culturally sustaining pedagogy (CSP). Further, it articulates the challenges for engaging CSP with students and teachers in a charter school context in which disciplinary and curricular mandates conflate cultural assimilation with academic achievement.