Objective/context: The purpose of this article is to present aspects of an ethnographic work concerning the borderlands mestizo theories that circulate in communities in the north of San Juan, Argentina, related to mineral extractivism, emphasizing the understanding of ontologies of the real that are constituted from historical experiences and modes of local relationality. Methodology: The work is based on the ethnographic study of the existing conflictive relations between the daily praxis and the local pluriverse narratives in communities of the north of San Juan, when expressing other ontologies of “the real” that disagree with the political projects of state and market incorporation-exclusion in these communities, conformed by humans, as much as by nonhumans, that cohabit these places and manage territories in their political act. Conclusions: It is proposed that the public political discussion, around the presence of mega-mining projects in the mountain water springs (glaciers) in San Juan, excludes the political and relational ontology expressed in the local borderlands mestizo theories. Originality: The article proposes reflections on the ontologies of neo-extractivist conflicts in Argentina, by opening questions with theoretical and methodological derivations not explored in the bibliography referring to the case of the province of San Juan.