My wife and I arrived at Devils Tower one bright sunny afternoon. We hiked around the tower, photographing prairie dogs and the Tower in the warm late afternoon light. I noted that there would be a full moon that evening and had wanted to experiment with night photography, so we returned after dinner. We had noticed several climbers on the Tower that afternoon who were still there that evening. They were spending the night on the Tower face, signaling each other with flash lights during my photo shoot.