A few days ago we drove up the road to the top of Mount Lemmon in Tucson Az. When we left the valley floor the temperature was 112*, and when we reached the summit it was a cool 67* with some rain and hail.  I saw this dead tree with some interesting clouds forming behind it and decided to find a small pull off area to make a photograph. I used a -10 ND filter along with a polarizing filter to get down to about a 90sec. exposure.  I was in a tight spot near the road on a fairly sharp corner and had to keep my focus on what was going on around me as I was in the process of making the image. I used a 17~40 mm zoom lens on my Canon 5D.  The effects of the moving clouds in the direction of the tree compliments the bare tree and gives a surreal appearance to the overall scene.

http://en.wikipedia.org/wiki/Mount_Lemmon