X2 on the Buffalo Bill Center in Cody. It is a world class museum complex. We spent the full day in there, from opening until they chased us out at closing, and we wished we could have stayed longer.
We really enjoyed the Blacktail Plateau Drive. It is unpaved and a little rough so most people pass it by, but the wildlife viewing was great.
The food stops (snack bars) can be a long time between. The distance may not be far, but expect frequent stops along the road for bear jams (traffic jams, where the everyone stops to look at bears or other furry woodland critters). It can take hours to drive only a few miles, so take a cooler filled with eats. Just be careful leaving it in the car if you stop to take a hike. A bear can open your locked car like peeling a banana. Besides... Who wants to eat in a crowded overpriced snack bar when there are ample little picnic spots with tables and restrooms and great views scattered all through the Park.
And extra memory cards for your camera... you will take a lot of pictures.