
The petroglyphs at Winnemucca Lake (courtesy University of Colorado)
Petroglyphs in western Nevada have been identified as the oldest of their kind in North America. Researchers at the University of Colorado Boulder conducted a study that dates the rock carvings to between 10,500 and 14,800 years ago.

Two images trace the shapes of some of the petroglyphs more clearly and show their relative size (click to enlarge)
The set of petroglyphs are carved deep into a wall of rocks at Winnemucca Lake. For the most part, the designs look abstract to modern eyes — series of wavy lines, diamonds linked together — but there are some that suggest natural elements such as flowers or leaves. “We have no idea what they mean,” University of Colorado Boulder researched Larry Benson, who led the project, said in a press release. “But I think they are absolutely beautiful symbols. … There are few petroglyphs in the American Southwest that are as deeply carved as these, and few have the same sense of size.”
Benson and his team based their findings on radiocarbon dating and a determination of the historical water levels of the Winnemucca Lake subbasin, which at a certain point would have been too high for the boulders in question to be exposed and available. Their results indicate that the limestone rocks containing the petroglyphs were exposed 14,800–13,200 years ago and again 11,300–10,500 years ago. “Whether they turn out to be as old as 14,800 years ago or as recent as 10,500 years ago, they are still the oldest petroglyphs that have been dated in North America,” Benson said.
The rock carvings previously thought to be the oldest in the US are located near in Oregon near Long Lake. There’s no estimated date for those, but one of the panels was carved at least 6,700 years ago, which is when a nearby volcano buried it in ash. By comparison, the oldest known rock art in the world was carved some 37,000 years ago — and it’s a depiction of a vulva.

Close-ups of the Winnemucca Lake petroglyphs