My sister is planning to go witht her husband and 3 kids in August. They're staying in Jackson Hole, and planning a day trip to Yellowstone. She's not quite sure where to start beyond that. Should she go by bus to Yellowstone or rent a car? How long a layover in Salt Lake is reasonable? What else do you suggest? I've planned the last 2 of her vacations (To Disney, of course!!) so now she's looking for help on this. Her husband just wants to be told where and when to show up, so it's all up to her. Anyone?