Unique combinations of geologic color and erosional forms decorate the Grand Canyon that is 277 river miles long and up to 18 miles wide, and a mile deep. The immense size of the canyon make it hard for our senses to understand. Nearly two billion years of Earth's history have been exposed as the Colorado River cut through layer and layer of rock. While you are visiting the Grand Canyon there are many different activities for you to do. You can go Fishing, Hiking, Biking, Boating, Wildlife Viewing and much more!