A mountainous shadow

I was treated to a better than average shadow the other night while getting ready to observe on Kitt Peak. Here is an image that shows our shadow along with some anti-crepuscular rays. The shadow looks a lot like a mountain in this photo particularly when you compare it with the Rincon Mountains that lay east of Tucson and are partly within the shadow. The shadow crosses the southern part of Tucson and the Rincons at this time of year as it moves southward with the northward setting sun from night to night as we approach the equinox. This image was taken at 55mm focal length with an exposure of 1/125 seconds at f/5.6, ISO 400.