The most well-known example is probably the enormous four-mile-long human figure in northern South Australia known as Marree Man which is both the largest example and also unique because it was created with apparently no witnesses whatsoever to the, presumably extensive, creative activity involved, and no artist or artists have ever come forward to claim it or been identified.
The term was coined by Robert Smithson, a major figure of the Land Art movement. Earthworks was first a science-fiction novel by Brian Aldiss, published in 1965, set in a world of environmental catastrophe. In 1967, Smithson took a copy of the novel with him on a trip to the Passaic River in New Jersey (where he created The Monuments of Passaic, 1967). He reused the title to describe some of his works, based on natural materials like earth and rocks, and infused with his ideas about entropy and environmental catastrophe.. Also in 1967 art critic Grace Glueck writing in the New York Times declared the first earthworks were done by Richard Saba and Douglas Leichter at the Skowhegan School of Painting and Sculpture in Skowhegan, Maine.