The Slow River That Carved the Canyon

In 1869, John Wesley Powell strapped himself to a wooden chair bolted to the deck of a small boat and led nine men into the unexplored depths of the Grand Canyon. What they encountered over the next three months stunned them — not the river's speed, but its patience. The Colorado River had spent six million years carving through limestone, sandstone, and granite, cutting a mile deep into the earth.…