313-Million-Year-Old Fossil Footprints Discovered in Grand Canyon

Visions of America/Joseph Sohm/Universal Images Group/Getty Images

At 277 miles long, up to 18 miles wide and over a mile deep at points, the Grand Canyon is one of the largest canyons in the world. Millions of people flock to the Grand Canyon every year to see its stunning beauty in person. And, some people have even made historic discoveries while exploring the vast canyon.