Descending some of the 277 miles (446km) of the Colorado
River in the Grand Canyon is a journey back in
time. Depending on the take-out point (others at
Whitmore Wash: river mile 187, Diamond Creek: river mile
225) and the type of watercraft, the trip can take
from 6 days to three weeks. On the first day out of Lee's Ferry (river mile 0), you see the Kaibab
Formation (230 million-year-old topmost layer of the mile deep Grand
Canyon) rise out of the river. By the middle of
the trip, you are surrounded by
2-billion-year-old Vishnu Schist at the bottom
of the Inner Gorge.
In between, The Marble Gorge, named
by Major John Wesley Powell, is dominated by
tall, vertical, brightly colored,
Redwall limestone cliffs that make it the most spectacular
section along the Colorado River.