Well, I don't know where to start, but I will give you the most important tips from our trip.
1. Reconsider the Rushmore thing and fly into Denver, or better yet, Jackson Hole. It's a lot of driving and it might be better to do it in 2 trips. We did it in one, but we started lots closer (from IL) and had more time. South Dakota is a looooong boring drive and you would have to do it twice.
2. Go as early in June as you can.
a. Small crowds.
b. Baby Animals.
c. Less Bugs.
d. There is a chance of snow (saw Old Faithful in the snow on June 7, but had the clothes for it so it was fun)
3. If you fly into Jackson Hole, stay for a day or two and enjoy Grand Tetons, then drive into the south entrance of the park.
4. Before you leave Jackson Hole, buy twice as much non-perishable food and drinks as you think you might need. A 6 pack of coke cans is $4 - $5 in the park.
5. Water buy/bring tons of water and drink it! Force your kids to drink even more. It's really easy to get dehydrated due to the altitude. The headaches are beyond awful.
6. Move to a different hotel every few days. I know that it seems like a pain, but you can't imagine how long it takes to drive 25 mile at 25mph not counting buffalo jams. And you really do get natural beauty burnout when you are driving for 45 minutes back ove the same road for the 10th time in 3 days
a. We started in Jackson Hole (stayed at the Ranch Inn) and went in the South entrance, did stuff as we went around the south loop. Stayed in West Yellowstone at the Hoilday Inn Sunspree (indoor pool and last TV), then moved to Mammoth (only a tub in the room - shower down the hall for 2 nights, then onto Dunraven Lodge (by FAR the most modern) and last we stayed in the cabins at Lake Yellowstone (scary 70's decor, but clean)
7. The food
a. In a word - YUCK!
b. I guess that the food is semi-ok, but there is very little variety. If you stay in the parks every hotel area has the same 3 things. A fancy sit down place (pricey and sloooow service), a cafateria - about that quality of food, and a limited hours picnic food place. The thing is that the menus are identical at all places with maybe one entree that is different and if you are staying for 9 days like we did, it gets boring. One of the places had a diner (I think it was Canyon) that was run by the people that do the concessions and that was a nice change. We had to go into Gardnier to get pizza (and do laundry since Mammoth didn't have a laundry)
Anyway, that's lots more than I planned to write, but I would be happy to give you more information if you want it
email or pm me
Lisa