Visitors to the Great Salt Lake who accidentally encounter Robert Smithson’s earthwork Spiral Jetty walk away wondering if it was built by visitors from another planet or college students with too mush time on their hands.

The fact is, Smithson built the earth sculpture – a 1,500-foot coil of black basalt rocks – in 1970. the artist was one of many who chose to build site-specific art outdoors in the West, away from the commercialism of urban galleries. He built the spiral out of black basalt rocks taken from the shoreline of the Great Salt Lake, arranging them to a height just above the surface of the water so people could walk on the earthwork as if on a pier.

Spiral Jetty is located at Rozel Point, about 100 miles northwest of Salt Lake City. The art is accessed by driving a 15,5-mile dirt road. Detailed directions are available at the Golden Spike National Historic Site. The jetty is not visible during times of high water.