It's a deep hole and it took a long time to get that way....

"Grand Canyon National Park is not permitted to give an official estimate of the geologic age of its principal feature, due to pressure from Bush administration appointees. Despite promising a prompt review of its approval for a book claiming the Grand Canyon was created by Noah’s flood rather than by geologic forces, more than three years later no review has ever been done and the book remains on sale at the park.” "