Utah's Newspaper Rock.

This is the Newspaper Rock or Tse' Hane (Rock that Tells a Story) records 2000 years of human activity near Monticello, Utah. Basically, passer-by people of the Fremont, Anasazi, Navajo, and other tribes add their own graffitti to the rock.

More amazing pictures at The Gigapixl Project's Portrait of America.