Went there during the winter, and my god every little bit of wild life was out!!! We seen Buffalo, Elk, Mountain Sheep, and a pack of wolves all on the side of the highway!!! It was a very picturesque place!!!
Make sure you spend enough time in this part of Yellowstone. It's well worth it. There are plenty of things to see and wildlife is in abundance. Sure, you'll see bison but there are wolves (provided you have a very good set of binoculars), bears (seasonal), coyotes and plenty of birds to be spotted. The scenery is spectacular with the river meandering through the valley. Visited in late September. The park was still very busy but this place is awesome.