Having been to Yellowstone once before, I knew the day is hard on the driver. When you're the driver, you can't fully enjoy everything around you.
This trip was beyond amazing. Our guide, Justin, picked us up promptly, from our location. He gave us a quick rundown of what the day would be like, offered us snacks and water, and we were off. He was very knowledgeable about all kinds of things during our ride to Yellowstone. Once in the park, he gave us great tips on seeing the attractions.
Plenty of "rest stops" along the way, as well as a great picnic lunch. Also plenty of opportunities to pick up mementos of your trip.
Be sure to ask for Justin - he was terrific!!