In recent years, the relationship between humans and the environment has evolved into a complex entanglement amid escalating environmental crises and the blurring of traditional boundaries between humans and nature, necessitating new approaches to examining this relationship. Posthuman ecocriticism, as one of the most prominent and emerging approaches in studying the relationship between human and non-human nature, can significantly contribute to a deeper understanding of this relationship from various perspectives including the reconsideration of human and nonhuman agency and the articulation of environmental ethics. In this light, the present library-based study by adopting a descriptive-analytical approach, aims to analyze the interbeing of human and non-human entities in the poems of the American poet Gary Snyder through the lens of posthuman ecocriticism. The main purpose of this paper is to discuss the ways Snyder represents the agency of non-human entities and challenge the anthropocentric paradigms in his poems. Through rereading Gary Snyder’s Pulitzer Prize-winning Turtle Island (1974), this study argues that, from a posthumanist perspective, Snyder extends the agency of non-human entities to the socio-political level to depict resistance to industrial and capitalist systems. Also, the departure from anthropocentrism and the emphasis on the interconnectedness of humans and the more-than-human world occupy a central position in the work of this contemporary American poet