Despite being one of the most famous and most-visited attractions in the United States, Grand Canyon National Park still holds some surprises. Here are a few facts about the Grand Canyon you probably don’t know.
7. We don’t really know how old it is.
It has long been believed that the Colorado River began carving the Grand Canyon about 6 million years ago, but a 2012 study contained a real shocker, suggesting that the process may have begun as far back as 70 million years. In all likelihood, the Grand Canyon as we know it today started out as a series of smaller canyons 70 million years ago, but the majority of the canyon did not begin to take shape until much more recently.