“There is nothing there, yet it is still a sculpture” – Michael Heizer In 1969, 23-year-old Michael Heizer instructed a work-crew provisioned with explosives and a bulldozer to tear two huge trenches into Mormon Mesa overlooking the Virgin River lazily meandering towards her consummation with the Colorado River in Lake Mead. The trenches, each 30 feet wide and 50 feet deep, face each other across a natural canyon in the mesa’s edge creating the 1,500-foot-long piece of land art Double Negative. The aerial image above shows the environmental sculpture viewed from north looking south. Approaching the work via the double …