The spectacle left one president in awe: "In the Grand Canyon, Arizona has a natural wonder which is in kind absolutely unparalleled throughout the rest of the world," said President Theodore Roosevelt in 1903 after seeing the canyon.
"I shall not attempt to describe it, because I cannot. I could not choose words that would convey or that could convey to any outsider what that canyon is," Roosevelt continued.
Today, looking down at the Colorado River at the bottom of the canyon, the awesome views leave visitors in wonder at how and when it was created. A new study published April 16 in the journal Science provides one answer.
According to the study, the Colorado River — which did not always flow through the Grand Canyon region — may have begun to carve its path through it after an ancient lake overflowed roughly 5.6 million years ago.
According to the authors, while other mechanisms like groundwater flow or erosion may have played supporting roles, their findings suggest that lake spillover was the primary process establishing the Colorado River’s course through the Grand Canyon.
