Nearly two billion years of Earth's geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted.Geologic Formations of the Grand Canyon National Park Service Retrieved November 17, 2009 While some aspects about the history of incision of the canyon are debated by geologists, several recent studies support the hypothesis that the Colorado River established its course through the area about 5 to 6 million years ago. Since that time, the Colorado River has driven the down-cutting of the tributaries and retreat of the cliffs, simultaneously deepening and widening the canyon.
nearly two billion years of earth's geological history have been exposed as the colorado river and its tributaries cut their channels through layer after layer of rock while the colorado plateau was upliftedgeologic formations of the gr.and canyon nat?ional park service retrieved november 17 2009 while some aspects about the history of incision of the canyon are debated by geologists several recent studies support the hypothesis that the colorado river es,tablished its course through the area about 5 to 6 million years ago since that time the colorado river has driven the down-cutting of the tributaries and retreat of the cliffs simultaneously deepening and widening the canyon