Scientists estimate the formation of the Grand Canyon as we know it today began approximately six million years ago, when the Colorado River began to carve downward into the bedrock. Over time, this process of slicing through the rock revealed the striking sedimentary layers which today are one of the Canyon’s hallmarks. Currently, there are over forty discrete layers which have been unearthed by the erosion process, and some of the rocks at the bottom of the canyon date back approximately two billion years.
One cannot consider the natural history of the Grand Canyon without also taking into account the human history of the area. To date, only approximately five per cent of the Grand Canyon has been extensively surveyed, but even this tiny fraction of the overall area has yielded archaeological treasures from ancient human occupation of the Canyon dating back between three and four thousand years.
As early as nine hundred years ago, the ancient Pueblo tribes made their homes around the Southwest, including the Grand Canyon. They chose their homes carefully to assure their people of safety in case of enemy attack, as it is much easier to attack an enemy across flat land than an enemy occupying a vertical fortification. This mode of life served them well until the coming of the Spanish conquistadores in the mid-sixteenth century. About thirty years after the Hopi led the Coronado expedition to the Grand Canyon, Major John Wesley Powell led the first successful exploration of the Colorado River. Grand Canyon tours became a popular pastime in the late 1880s with the advent of train service to the Canyon.
In 1893, President Benjamin Harrison declared the Grand Canyon a forest preserve. Theodore Roosevelt later cemented the Grand Canyon’s status as a national park and hunting preserve in 1908, but it wasn’t until 1920 that automobile traffic to the park outstripped that of people coming to the park by train. The area doubled in size in 1975 as a result of the Grand Canyon National Park Enlargement Act, signed into law by Gerald Ford.
Today, the Grand Canyon remains an archaeological and natural treasure trove and is actively protected as a World Heritage Site. Tourists continue to flock to the area today, to marvel at the incredible beauty of this area and the immense time scales in plain view there. Today, tours to Grand Canyon remain a major part of the Arizona and Southern Nevada economy, and aggressive conservation efforts are underway to ensure the canyon remains spectacular and beautiful for generations to come.