Built at the mouth of a terminal basin rich in minerals and nearly devoid of life, ​Spiral Jetty ​is a testament to Smithson’s fascination with entropy. Its precarious location lends itself to the structure’s inevitable disintegration, yet its impressive size and deliberate shape command the surrounding landscape. Constructed from 6,650 tons of rock and earth, the spiral continuously changes form as nature, industry, and time take effect.

In 1999 Nancy Holt and the Estate of Robert Smithson donated the earthwork to Dia Art Foundation, who continue as stewards.

Robert Smithson made the film Spiral Jetty on returning to New York from Utah, after completing his landmark earthwork of the same name in April 1970. Spiral Jetty is located on the Rozel Point peninsula on the northeastern shore of Great Salt Lake. Made from over six thousand tons of black basalt rocks and earth collected from the site, Spiral Jetty stretches 1,500 feet long and 15 feet wide in a counterclockwise spiral. As well as the earthwork and film, Spiral Jetty is the title of an essay Smithson wrote in 1972.