In this chapter, John McDowell proposes ecoperformativity as an explanatory model for how expressive culture functions in settings of ecological debate and conflict. He analyzes the referential and performative dimensions of traditional ecological knowledge (TEK) among Indigenous populations of the Otavalo region of Ecuador and Colombia’s Sibundoy Valley, demonstrating that TEK speech acts ground human communities and empower them to take action to defend their relationships with each other and with nonhuman others. Attending to dimensions that render performances of ecological knowledge effective and that move people to action, McDowell makes a strong argument for recognizing expressive culture as a vital tool for both resisting and negotiating environmental change.