Lee's Ferry is the traditional starting place for most river runners. Approximately 150 people enter the river here each day - in paddle boats, row boats, kayaks, and big motorized rigs like the one I was on. The mechanized trips take five days; the luddites take twelve. We arrived at the launch before our boat did; after a short delay we were off.

One thing that takes some getting used to is the extremes the canyon presents. The Colorado River is very cold upstream. This condition is not a natural occurance; it is caused by the Glen Canyon Dam some 7 miles upstream. The water leaves the dam 70 meter below the surface, and is a constant 47°F. With daytime temperatures commonly exceeding 105°, the contrast between being wet and dry is bracing, and is always changing.

Near the end of our first day, we visited the famous Red Wall Cavern, a wide, shallow cave carved out of the redwall limestone by the rushing river. A number of fossils were plainly visible in the rocks there. In geological time, these fossils are between 320 and 360 million years old (Mississippi Period). During that time, this part of the earth was actually a shallow sea. The limestone is composed of untold numbers of shells, the remains of ancestors of today's molluscs, corals, sponges, sea lillies (crinoids), and other aquatic animals.