There is a well-known story among photographers about a photo-journalist who succeeded in getting a picture of a man who had jumped from a tall building while and was still falling. The photographer showed the picture to an associate who thought it was no great accomplishment. "It was just f/8 and be there" he said.
This picture is about the same. The trick was to be there. If you spend enough time out and about and looking for pictures, you occasionally get lucky. I was solo backpacking in the Smokies in the summer of 1978, and in the late afternoon, on Mt. Sterling, I discovered an old fire lookout tower, then no longer in use. I climbed up the tower as far as possible, at about the right time, and there it was. I was there, and I had brought my f/8 with me.