The Grand Canyon is one of the most spectacular geologic features on planet Earth. It is 277 miles long, up to 18 miles wide in its western portion, and over a mile deep. We will take a “trip” from the bottom to the top of the canyon. Along the way, we will visit ancient rock formations almost 2 billion years old. On our way up, we will view the caves in the Redwall Limestone and discuss how these caves hold important clues to the canyon’s incision and evolution. Finally, we'll watch a National Geographic video, Birth of the Grand Canyon, that presents the most recent theories on when the Grand Canyon was carved in order to answer controversial questions. How old is the Grand Canyon? Was it carved entirely by the Colorado River in the last 6 million years, or did parts of it form long before that time?