What happens when what might otherwise have been another conservation land grab becomes, through a tensely negotiated land transfer, a conservation collaboration on titled Indigenous land? Drawing from political ecology, decolonial scholarship and Indigenous theory, this research takes seriously competing knowledges about nature and the plurality of natures that these embedded knowledges are responsible for producing. In encounters between differently situated knowledges and world-making practices, exclusions are produced through co-constitutive, mutually reinforcing hierarchies that are both epistemological and material. But what if the terms of this exclusion are renegotiated? In an area layered with histories of settler-colonialism and land struggles, a large tract of land in Misiones, Argentina, was purchased by an international conservation NGO in 2012 but transferred to three Mbya Guarani communities residing there. I use the elaboration of a collaborative conservation plan for this land to understand translation and negotiation between knowledge practices and interrogate the impacts of these translations on environmental management. Through two phases of research over twelve months I use content analysis and ethnographic methods to understand a) the discursive and legal limits to conservation and their relationship to Mbya Guarani world-making practices; b) the translation across epistemologies necessary for collaborative conservation; and c) the impact of this encounter across difference on the environmentalists and scientists who shape conservation policy and discourse. By privileging the contact zone where negotiation between environmental knowledges occurs, I examine the impact of Mbya Guarani on the processes that shape their ability to materially and relationally reproduce their worlds. In doing so, I ask how we might reimagine environmental management through decolonial imperatives.