A seminal figure in late 20th-century art, Robert Smithson created a dialogue between traditional sculpture (non-site) and its context (site). For him, the relationship between the material that makes up the work and the material's origin was a crucial component of the work of art itself. Smithson was fascinated by science fiction and ecological and geological processes; by the non-space of movie houses, suburbia, abandoned industrial areas, and strip-mined land; and, most importantly, by the concept of entropy. This monograph presents a comprehensive collection of Smithson's writings between the years 1965 and 1973. From his origins as a New York School painter in the early 1960s to his work in Post-Minimalist sculpture in the mid-1960s and his role as a leading and defining member of the Land Art movement in the late 1960s and early 1970s, the importance and influence of Smithson has been widely acknowledged. Also included are a critical essay on Smithson's career and a wide selection of his artwork.