Photo of the Day 21 January 2008

Colorado River at Granite Rapids, Arizona, 2005
Photograph by Michael Nichols
A time-lapse image blurs the silty, mocha-colored waters of the Colorado River as it flows through sheer cliffs in Grand Canyon National Park. The now tame Colorado carved these steep walls over the last six million years, exposing rock strata that detail nearly two billion years of North America's geologic history.

Wrote one canyon trekker: "[T]hat I could reach down and touch a part of the Earth that existed when life itself was a mere billion-plus years old made this big cliff land seem very holy indeed."