Critics and readers alike recognize Ammons's achievements: in 1973, his Collected Poems won the National Book Award for Poetry; in 1975, his long poem Sphere: The Form of a Motion was nominated for the National Book Award and received the Bollingen Prize for Poetry: in 1977, he received and award from the American Academy and Institute of Arts and Letters. The Snow Poems, Ammons's twelfth book, is a major achievement by a major American Poet.