In this study, we examine how the Waimiri Atroari (Kinja) articulate environmental conservation through Indigenous territorial governance in the Brazilian Amazon under conditions of sustained external pressure. Using a qualitative case study approach grounded in long-term engagement with the Waimiri Atroari territory and institutional programs, we analyze how biodiversity protection emerges from the integration of territorial surveillance, sociocultural continuity, adaptive resource management, and responses to large-scale infrastructure projects imposed on Indigenous lands. The Kinja maintain approximately 2.5 million hectares of forest through coordinated strategies that include monitoring illegal activities, mitigating the impacts of the BR-174 highway through wildlife roadkill monitoring and waste management, and participating directly in environmental oversight associated with the 500 kV Manaus–Boa Vista power transmission line. These practices demonstrate that conservation in the territory is not an isolated environmental objective, but part of a broader socioecological system combining traditional knowledge, social organization, and technical adaptation. Despite contributing to biodiversity conservation, challenges related to population growth, climate change, and persistent external pressures continue to affect the long-term sustainability of this model. Although the Kinja experience is not directly transferable to other contexts, it offers important insights for conservation policy, particularly regarding the centrality of Indigenous governance and the integration of knowledge systems in Amazonian environmental protection