Another vote for Grizzly. Fishing Bridge is centrally located and has FHUs but is VERY tight and IMO not all that comfortable. Granted, you're not in Yellowstone to hang out at the campsite all day, but... Cody, even the CGs west of it, are still quite a drive from most of the park. Grizzly is at least just a few blocks outside the west gate, and about 1/2 hour from Madison Junction in the park. The drive from outside the east gate will be longer to Fishing Bridge Jct, more like an hour. Staying in Deadwood to tour the Black Hills is just not comparable - Yellowstone is a much bigger area.