In 1903, President Teddy Roosevelt rode a train to the South Rim of the Grand Canyon
, and declared the scene “one great sight every American should see.” And people have flocked there ever since – annual visitation at the park now numbers four-point-five million. And while most people understand the Colorado River carved the Grand Canyon… you might be surprised to find out that geologists are still trying to figure out just *how* and *when* the canyon was formed. We'll talk with a geologist
who is trying to answer those questions.
Wayne Ranney, author, "Carving Grand Canyon: Evidence, Theories, and Mystery"