This May 2012 photo provided by the U.S. Geological Survey shows ancient carvings on limestone boulders in northern Nevada's high desert near Pyramid Lake. The carvings have been confirmed to be the oldest recorded petroglyphs in North America - at least 10,500 years old. The findings were published August 2013 in the Journal of Archaeological Science. This site was once the shoreline of the now dried up Winnemucca Lake.
Researchers have discovered what they say are the nation's most ancient rock carvings — known as petroglyphs —located in Western Nevada
The carvings may date back more than 10,000 years ago.
Larry Benson of the US Geological survey and the University of Colorado Boulder led the research on the rocks. He joins the show with more.