It was a very cold but sunny day this winter season in Yellowstone National Park. The bisons were migrating from higher elevations to the warmer lower geyser basin for their food - snow covered grass on the ground. The bisons were very cautious while walking on the hot springwater covered grounds. The blue sky, the snow covered dead tree trunks, the reflections from the springwater, steams from the Silex Spring together with the bisons composed a very unique scenery in Yellowstone.