The 2012 trip to Yellowstone was great, but we were limited in our travel and our ability to photograph the park because of all of the snow.  I decided then that I wanted to return, again in the winter.  Two years later, I did.  We has a little snow, but this time we were challenged by the cold.  I don’t think that it ever got above 17F for the entire time and one morning, we were delayed because the temperature was -24F.  Now that was cold.