Tom and I rode part of the 24 hours in the Old Pueblo race course north of Tucson. Every time I come to the desert to ride I have to remember that all the plants can bite, claw, or poke. Nothing down here is soft or forgiving. We went early to beat the heat and were treated to a wonderful ride sprinkled with wildlife. And cows.
We also rode some local trails near Oracle and one that looped down near Biosphere 2. The mid-May riding is good if you start very early though I suspect riding this area in the winter is much nicer.