Study: Grand Canyon 70M Years Old, Not 6M Which means dinosaurs might have roamed there, say researchers By Kevin Spak, Newser User Posted Nov 29, 2012 2:44 PM CST 56 comments Comments In this 2006 file photo, tourists visit the Hualapai Indian Reservation along the western end of the Grand Canyon. (AP Photo/Jake Bacon, File) (Newser) – Visit the Grand Canyon, and signs will inform you that scientists believe it is about 6 million years old, which, a new study suggests, is a mere 64 million years or so off. A group of "contrarian" geologists published a paper today arguing that the canyon is about 70 million years old, meaning dinosaurs could have roamed its depths, the Washington Post reports. The finding is based on a technique called thermochronology, which studies tiny crystals for signs of elemental decay that would only occur near Earth's surface. Lead author Rebecca Flowers of the University of Colorado believes the canyon was not, as conventional wisdom holds, carved by the Colorado River, but by two other ancient rivers; the Colorado just took advantage of the existent path. "We know it's going to be controversial," Flowers says. And she's right. "It is simply ludicrous," says one noted canyon geologist, who worries the theory will confuse canyon-goers. "To them, it seems like dinosaurs might have lived with humans (like the Flintstones)."