Robert Smithson was an American artist born in 1938. He was most famous for his land art. He initially identified as a painter, but then moved on to sculpture. His initial sculptures were unique in their use of glass sheet and neon tubing, which he used to explore visual refraction and mirroring.
In 1967, Smithson became fascinated with dump trucks, which he witnessed moving earth and rock in industrial areas in New Jersey. Inspired, he began to create site and non-site land art. Site art was work created in a specific outdoor location. An example of this is Smithson's work titled, Spiral Jetty, which is located in Great Salt Lake, Utah.
Non-site work could be displayed anywhere, including a gallery. It often consisted of a photograph of a site work alongside actual material that would have been used to create a piece of land art.