Because of their perceived malleability, young people have been central to efforts by modern settler states to erase and displace Indigenous populations in order to control land and resources. In Canada and the United States between the late nineteenth and mid-twentieth centuries, these efforts (which were always contested) focused largely on Indigenous child removal and assimilatory schooling. Well-known as sites of abuse, hunger, disease, and premature death, state-funded and state-run Indian boarding schools in both countries were also shaped by the development of distinctive peer cultures. This chapter uses secondary literature, archival sources, memoir, and oral history to better understand the lived experience of Indigenous young people at these carceral and genocidal institutions. At Indian boarding schools on both sides of the Canada-U.S. border, Indigenous students used language, labor, performance, mischief, and sport to invest in and support distinctly Indigenous youth cultures characterized by imagination, resistance, solidarity, and critique.