Processes of environmental dispossession have had dramatic consequences for dietary quality, cultural identity, and the integrity of traditional food systems (TFS) in many Indigenous populations. These transitions have not been documented among First Nation people in southwestern Ontario, and virtually no studies have investigated TFS in southern or urban regions of Canada. Nested within a larger community-centred project designed to better understand the social and spatial determinants of food choice and patterns of food security, the objective of this paper was to explore First Nation mothers' knowledge about access, availability, and practices relating to traditional foods in the city of London, Ontario, and nearby First Nation reserves. In 2010, twenty-five women participated in semi-structured interviews that were audio recorded, transcribed, and analyzed with input from community partners. Our results centre on the women's stories about access, preferences, knowledge, and sharing of traditional foods. Those living on a reserve relied more consistently on traditional foods, as proximity to land, family, and knowledge permitted improved access. Urban mothers faced transportation and economic barriers alongside knowledge loss related to the use and preparation of traditional foods. Overall our results demonstrate uneven geographic challenges for First Nation engagement in TFS, with urban mothers experiencing uniquely greater challenges than those residing on a reserve.