Started out in Bozeman, stayed a first night in Mammoth Hot Springs, stayed several days around Old Faithful, and then back to the Mammoth Hot Springs area for the Wolf Discovery tour.
Bison at Silex Spring Lower Geyser Basin, Yellowstone National Park, Wyoming
A few seconds later, the bisons silhoutte appeared through the steam. It would have been a great shot but I was too slow. - February 06, 2011 - 1/640 sec at f / 13 - 28 mm - ISO 400 - 44°33'0" N 110°48'22" W