Interesting facts about the Grand Canyon are that its oldest rocks date back two billion years, it represents one-third of Earth's history and it's not the biggest canyon in the world. The Grand Canyon ranges in age from 250 million years old at the highest rocks to two billion years old at the lowest rocks.
Grand Canyon Explorer explains that scientists distinguish more than 30 percent of the history of the Earth in the rock of the Grand Canyon, from the oldest metamorphic and volcanic stone deposited in the Proterozoic Era to the youngest sedimentary rocks deposited during the early Mesozoic Era. These layers of stone read like a map of the Cambrian, Devonian, Mississippian, Pennsylvanian and Permian periods. This canyon was created through the gradual process of erosion, volcanic activity and ancient waterways.
Despite its popularity, the Grand Canyon is not the largest canyon on Earth. With an average depth of 5,280 feet and length of 277 smiles, it comes in a distant second to the Yarlung Tsangpo Grand Canyon in the Himalays, which boasts a depth of 17,567 feet and a length of 308 miles. However, it still takes tourists from one two three weeks to travel the length of the Grand Canyon via the Colorado River.