Thimble Peak (on the left) stands between Sabino Canyon and Bear Canyon in the Santa Catalina Mountains. I've noticed that viewed from the track, the space between Thimble Peak and Blackett's Ridge (to its right) echos the inverted shape of Thimble Peak, more or less, depending on where I stand.
The first image is from the sunrise skywatch post on my Desert Colors blog. The second picture was taken twelve hours later. The cloud formation looks like a ghost of Thimble Peak.
I found some more pictures of Thimble Peak that I took earlier this year in various lighting and weather.
I'm fascinated by the colors of Thimble Peak and the negative space next to it. I plan snap a picture each time I go to the track over the next few months and post some of the results.