How the Grand Canyon Was Formed

The astounding beauty of the Grand Canyon was born of a violent and turbulent past. A common

statement is, "The Grand Canyon was formed by the erosion of the Colorado River." While this

is somewhat true, it doesn't tell nearly all of the story. Just consider: many other ancient rivers

have flowed the same pathways for millennia without carving the terrain into a mile-deep

canyon. So, what happened in the area we now call Arizona had to be different.

The Origins of the Terrain That Allowed the Grand Canyon to Form

Many years ago – 300-350 million years – tectonic forces lifted the rock that now lines the walls

of the canyon into an enormous plateau nearly as high as the Himalayas, as one geologic plate

slowly slid under another. It is estimated that the mountains reached four to six miles in height.

Eventually, the winds and rains eroded this impressive range into a flat plain. It is about this time

that the Colorado River began making its way through the area.

Geological forces again raised the area into a second mountain range, though not likely as

impressively grand as the first. This second range cut off the natural flow of the Colorado River,

causing it to divert to the southeast and forming Lake Bidahochi. Undeterred, the Colorado

ebbed away at the blockage, eventually rejoining itself. This led Lake Bidahochi to drain. The

winds, rains, and continual freezing and thawing of the region finally eroded away the second

mountain range.

The Formation of the Grand Canyon

The area eventually sank beneath what had been the inland sea. The sea life here, including

primitive shellfish, fossilized and became embedded into the rock, forming a tough layer of shale

rock, which is one of the many layers in the canyon walls you can see on a Grand Canyon Scenic

Airlines tour today. The Colorado River continued to eat away at this rock making the canyon

deeper. But the river didn't cause the canyon to widen; it had help from all of the debris blowing

through the canyon to carve a wider path. The area now lies in a remote desert, trying

desperately to hide the secrets of its violent past by providing some of the most serene sunrises

and surreal sunsets on the globe.

Modern Exploration of the Grand Canyon

Until 1540, the gorgeous spectacle we now call the Grand Canyon was the sole property of the

Native Americans and the natural world that gave birth to it. That year, Coronado's expedition

found the area -- the first Europeans to do so. However, his team had trouble navigating the

treacherous terrain within the canyon, particularly the tumultuous Colorado River. Established

society more or less left it alone after that, until the late 1860s.

In 1869, John Wesley Powel, the first modern explorer who ventured to the canyon, was able to

successfully navigate the Colorado River. Though he lost two of his boats in the process, he

proved that this corner of the Wild West could, in fact, be tamed. The tales of glorious rock

formations, unbelievably fabulous sunsets, and a canyon as deep and wide as any on earth got

back East to John Hance. He saw the opportunity to make some good money, and began the first

Grand Canyon tours in the 1880s.

Hance's tours and the tales brought back by his customers helped spark interest in westward

expansion.