North America's Oldest Petroglyphs (IMAGE) University of Colorado at Boulder Caption A CU-Boulder-led team has found that petroglyphs discovered in western Nevada date to at least 10,500 years ago, making them the oldest rock art ever dated in North America. Credit University of Colorado Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.