This paper reflects on the possibilities and limits of participatory mapping as a tool for interrogating the power–knowledge inequalities that structure indigenous peoples’ engagements with postcolonial state cartography and bureaucracy. I describe mapping activities conducted in a remote Guaraní community in the Bolivian Chaco as part of a research project exploring the dynamics and legacies of Native Community Lands, a national indigenous land titling programme. While these exercises were designed to explore the disjunctures between state and indigenous knowledges of territory, they generated unexpected power dynamics that led me to reflect more deeply on the power of maps, the pitfalls of ‘countermapping’ as an activist practice and my own imbrication in a bureaucratic field of power. The paper concludes that participatory mapping can be a fruitful if ambivalent method for studying state bureaucracy, which demonstrates the value of examining the legal-cartographic knowledges of the state ‘from the margins’ – including from the perspective of the people and places they claim to represent.