For more than a century, evolutionary geologists have tried to explain how the Grand Canyon in the United States might have formed slowly over millions of years. Ideas that the Colorado River eroded the canyon, or that enlargement of streams and gullies caused it, have been shown to be improbable. Both these theories have a difficult time explaining where the products of tens of millions of years of river erosion went.

Study the Kaibab Upwarp. It's a serious problem for evolutionists.