The US state of Arizona has some of the largest collections of historical Native American art. Most of them were created by chipping and scraping the top surface of the basalt boulders to expose a lighter layer underneath. Some of the rocks have been shot at, graffitied or had paint thrown over them. Artist Christopher Short, who is descended from the Citizen Potawatomi Nation, believes the petroglyphs are connections to the past and need to be preserved. I'm basically turning rock art into science-fiction.