What is the Grand Canyon made of?

The Grand Canyon is made of sedimentary rocks. Sedimentary rocks are formed when sediment, such as sand, mud, and pebbles, is compacted and cemented together. The Grand Canyon's sedimentary rocks were deposited over millions of years by the Colorado River and its tributaries. The different layers of sedimentary rocks in the Grand Canyon tell the story of the Earth's history, including changes in climate and the movement of the Earth's crust.