All of the photo's below were taken by Laura Crossey and are used with her permission.
View from the Prescott Resort to the northeast. The colorful, exposed rocks in the middle distance belong to the Dells Granite, a 1.4 billion year intrusive rock that is now fractured and beautifully sculpted. In the far distance and barely visible are the San Francisco Peaks near Flagstaff. This is a remnant stratovolcano with a collapsed top that forms the circular ring of peaks. Its former height before collapse may have been over 15,000 ft. St. Matthews Mountain (6,307 ft.) is visible on the left between these two features and is likely composed of volcanic rocks between 15 and 10 million years.
Karl Karlstrom getting the field trip started in front of the Bright Angel Hotel. Karl has done a lot of research in the Grand Canyon, beginning with the Precambrian basement rocks (Vishnu Schist and Zoroaster Granite), the Grand Canyon Supergroup, and recently ideas for how and when the canyon formed.
Karl and I in front of the portal at the Precambrian end of the trail. Here we discussed the origin of the idea for the Trail of Time and its uses in geologic education.