As we all know, the Bushies and their religious right nutjobs declared a "War on Science".
Here is a quote from the AlterNet Blogs regarding the Grand Canyon:
"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.
Furthermore, a book approved by the Service claiming the Grand Canyon was created by Noah's flood, rather than by geologic forces, is on sale in the park for more than three years, even though a review was promised to Congress and the press. A Freedom of Information request [PDF] reveals that no review has ever been requested, nor taken place.
"In order to avoid offending religious fundamentalists, our National Park Service is under orders to suspend its belief in geology," stated PEER Executive Director Jeff Ruch."