Bison, more commonly called Buffalo, are the success story of Yellowstone National Park. At one point, there were less than 40 Bison in what are now the lower 48 states. In the early 1900's, an attempt was made to try and bring them back from the brink. The remaining Bison were bred with cattle to help strengthen the gene pool. All of the Bison in the lower 48 states are descendants of these cross breeds.

When it gets cold (as it does frequently during the Yellowstone winter), these animals will "hunker down" in the snow to help block the wind and preserve heat. Of all the image that I took that week, this is, by far, my personal favorite.