Part 3, Chapters 1-5 Summary and Analysis

Part three begins with a map of the simplified profile of the geology of the Grand Canyon. The map includes a schematic of the eight layers of the canyon from the top of the Rim to down below the Tonto Platform and the Inner Gorge. It is important for the reader to understand how the canyon was formed. The author includes a great amount of detail in the text regarding the layers and their unique characteristics. The reader can also see how the differences in the layers affect Fletcher's journey.

Layers 1-3 are referred to as the Rim.

The first and youngest layer, which is comprised of Limestone, is approximately 400 feet thick and holds the current age estimate of 225 million years.

The second layer, which is comprised of Sandstone, is approximately 350 feet thick and holds the current...