In Canada, First Nations are placing increasing emphasis on youth perspectives in their political and territorial self-determination projects. This article presents a one-day participatory mapping workshop carried out as part of the ‘Tshishipiminu’ research partnership (2011 to 2019) between geographers at Université Laval and Pekuakamiulnuatsh Takuhikan, the political authority of the Ilnu Nation of Mashteuiatsh (Quebec). The workshop was conducted in April 2016 with young Pekuakamiulnuatsh aged 15 and 16 to document their representations and practices of the territory. The activity used maps and objects as supports for collective discussions, and sketch mapping as a means of expressing lived spaces. The workshop showed that while not all young people have a political vision of their territory, they generally continue to practise activities linked to Ilnu culture (hunting, fishing, handicraft, etc.). Moreover, the colonial and industrial transformations of the territory have not prevented them from feeling a sense of belonging to it. Finally, they are reappropriating colonial spaces, including ilnu assi (the ‘reserve’) which has become a marker of identification.