Re: Yellowstone Trip
Plateau Angler is correct, I always end up staying most of my time in the Lamar Valley, but the last two trips I got camping reservations in Madison (central location), see lots of animals in the ealy morning drives. Old Faithful Inn and Roosevelt Lodge is where I shower, plus Roosevelt food is great and affordable. I'd say to drive out the East entrance to Cody and back to the NE entrance (Silver Gate) on the Chief Joesph Hwy. and over the Beartooth Hwy to Red Lodge, will be worth your time.
What I do is get camping reservations and use them if I have to, but if Slough has a slot get it (I never been that fortunate) or Pebble Creek, have one person to stay in your new campground and go and cancel other, only cost you a night cost.