Colorado River Audiocasts
From the Grand Canyon National Park River Information Center
Three Mp3 audiocasts made from Grand Canyon National Park's Non-commercial River Trip Orientation Video may be played through you device or downloaded via the links below.
Did You Know?
The more recent Kaibab limestone caprock, on the rims of the Grand Canyon, formed 270 million years ago. In contrast, the oldest rocks within the Inner Gorge at the bottom of Grand Canyon date to 1.84 billion years ago. Geologists currently set the age of Earth at 4.5 billion years.