Probably should have explained the Jetty a bit, it is an "installation" art piece literally installed into the Great Salt Lake. It was done by an artist by the name of Smithson and it think it was in the seventies? not sure of the date.
The area surrounding the lake is covered in black igneous rock, the bed of the lake is white from salt deposits, sometimes there is an algae bloom which turns the water red. Smithson wanted to play off the colors of the water, the rock, the algae (and when the rocks had been submerged by water rise and fall they become encrusted with salt crystal), the contrasts between the black rock and sparkling crystal.
The dike itself and massive rocks were laid by a company in my own town, about an hour or so away from the sight and about a half an hour away from the Golden Spike monument, where the last spike of the trans-continental railway was laid.
The Jetty is off a small promontory in the shore line and juts into the lake, it is simply a gigantic spiral of black rock.
The west desert of Utah is spare, wild, outrageously beautiful, barren, windswept and an extaordinarily odd place for an art installation and yet there it is. Smithson is gone now, he was killled in a airplane crash, but the Spiral Jetty is still there and still seemingly solid and unmoved.