Colorado River’s connection with the ocean was a punctuated affair

The Colorado River’s initial trip to the ocean didn’t come easy, but its story has emerged from layers of sediment preserved within tectonically active stretches of the waterway’s lower reaches. Researchers theorize that the river’s route off the Colorado Plateau was influenced by tectonic deformation and changing sea levels that produced a series of stops and starts between roughly 6.3 and 4.8 million years ago.
Geology News — ScienceDaily