imitating them , i could hike to the top of tumamoc hill or to the backside of the rincon range , through the twiggy palo verde trees which in late may are full of rattling and blaring apache cicadas , huge gray gnats with terrible great eyes , the gray of their bodies showing veins of white like the curly white hairs blooming from and crisscrossing the head of a middle-aged woman , until i could find one of the ready-made grinding holes , in a red , brown or black boulder .