When I was at the garden on Sunday morning I spotted a flash of white on the Papago Buttes but I couldn't tell what was going on. So, I extended the telephoto and snapped a few photos as I walked along one of the trails.
After I downloaded the photos, I could see that it was a couple preparing to do a little rock climbing on the butte.
I took this las shot as I was leaving. They were still up there practicing their climbing techniques.