By Sid Perkins
It would be difficult to find anywhere else in the world a spot yielding so much subject matter for the contemplation of the geologist; certainly there is none situated in the midst of such dramatic and inspiring surroundings.
—Clarence E. Dutton, 1882
As many as 5 million people each year visit Grand Canyon National Park. Most go for the majestic view, but geologists go to the canyon—a gaping chasm more than 275 miles long, up to 18 miles wide, and in places more than a mile deep—to unravel its untold tale of erosion writ large.