Oldest North American Rock Art May Be 14,800 Years Old

August 15.

Ker Than of National Geographic has written an interesting article about some "Nevada petroglyphs which could date back to the first peopling of the Americas". 
For the full text visit the National Geographic article here.

"Ancient symbols etched onto the sides of boulders lying along the western edge of a desiccated lake in Nevada are the oldest confirmed rock carvings in North America—possibly dating back to the first peopling of the New World, scientists say."