I have taken numerous winter trips to Yellowstone National Park to photograph the wildlife there. It's commonplace to find bison there, so in winter, I try to capture snow-covered bison in their harsh winter environment.
Last month, I took a snow coach tour into the interior of Yellowstone National Park. About an hour into the drive, the coach stopped by a large open field with a small bison herd about 200 yards away. It was snowing, and the bison were covered in snow.
I focused on a group of four bison and took a series of images, hoping to capture three of them facing toward me simultaneously. The faces of the three were crusted with snow after they had been using their muzzles to push aside snow and uncover grass underneath. One bison was munching grass in its mouth as I shot. The bison were barely moving, but I used a fast shutter speed (1/1000 second) to freeze snowflakes that were falling between me and them.