This paper aims to examine poems of five modern American poets, including Wallace Stevens, A. R. Ammons, Adrienne Rich, Charles Wright, and Gary Snyder, which pay the profound respect to the ontological autonomy of nature through reflections on the limitations of human mind and language. Words are arbitrary abstractions which erase the individual differences of things in nature; therefore they are sheer emptiness, compared with the substance of the things as they are. By revealing this essential emptiness of words, the poems examined in this paper acknowledge the ontological autonomy of the nonhuman world which exists beyond human language, which is a key factor of environmentalism and ecology. Stevens`s "The Snow Man" and "The Course of a Particular," show the mode of experiencing the dehumanized reality of nature by restraining human consciousness and pathetic fallacy. Ammons` "Corsons Inlet" also concerns the risk of imposing arbitrary order on nature when we represent ever-changing natural phenomena. In "Rural Reflections", Rich recommends "Inhuman patience" or rhetorical abstinence which enables us to see and enjoy nature as it is. Charles Wright`s "Reading Lao Tzu Again in the New Year" develops from rhetorical excess through linguistic skepticism to tight visual images which aim at the proximity to things as they are. The ecological orientation of Snyder`s "Ripples on the Surface" is determined by his understanding of elusiveness of nature and his effort not to trap it in the prison house of language.