Striking fall color dotted the cliffs of Pumphouse Wash, a beautiful hike up a slot canyon that carries water from the Colorado Plateau to Sedona.

Arizona is home to some of the most diverse and beautiful desert landscapes I have ever seen. I started out in the Mohave this morning. Despite being desolate and poverty stricken, this region looks like a scene from Mars; no wonder the UFO people love it.

Next I arrived in Flagstaff, on the Colorado Plateau, where the high desert is characterized by conifers, meadows grasses, and wildflowers.

Descending the Colorado Plateau, I was struck by fiery Fall color lighting up steep canyons of conifers and Coconino sandstone cliffs. Here I found Pumphouse Wash, and hiked up it. Red oaks, big leaf maples, cottonwood, and aspen share the walls of the canyon with several species of conifer.

The greenhouse inside the Flagstaff Arboretum's innovative horticultural research and propagation center. In the background are plastic tubes filled with water. This passive solar system heats up during the day and keep the plants warm at night. The tubes also help cool the greenhouse during the day.