The Dia guide presents Spiral Jetty as a work whose identity is inseparable from geological transformation. Built from black basalt and earth at the edge of Great Salt Lake, the coil is continually altered by water levels, salt crystallisation, drought and biological colouration. Smithson’s iconic operation is to make entropy perceptible without converting landscape into static monument. The work is walked, submerged, re-emerged and documented; its temporality exceeds any single viewing. Methodologically, the guide situates Spiral Jetty within Smithson’s broader concepts of Site and Nonsite, accumulation, displacement and peripheral territory. The wider bridge reaches Land art, environmental history and media documentation. The sculpture exists simultaneously as earthwork, film, photograph, journey and changing material condition. Its enduring contribution is to redefine permanence: persistence does not require stability, and a work may retain identity precisely through continuous alteration.