Sounds like you've planned well. Enjoy the park. Grant will allow you easy access to Grand Teton National Park. Remember, the park is big and travel can be very slow. Park visitors can block a road very quickly while observing wildlife. Likewise the wildlife, especially the bison, will frequently take over the road and there is no moving them if they don't want to be moved.
We just got home from a trip to the same places. After being in Yellowstone and the Grand Tetons, South Dakota was a bit of a let down. I wish we had spent more time in Wyoming. However, visit Wind Cave National Park, just south of Custer State Park. Have fun, I wish I was still out there!
What I would suggest is taking less time in South Dakota and taking a trip to see Glacier National Park. The National Parks of Montana and Wyoming are awesome!
Not sure of what way you are going home, but if you are driving across Wyoming, stop and see Independence Rock, you can climb up on top of it and see all the signatures from people who were on the Oregon Trail. Even my crabby teenager liked that.
One thing we learned was to split the time between Yellowstone and the Tetons. We found after a few days we wanted to see something besides bubbling pots and went to the Tetons, then after a few days in the Tetons we went back to Yellowstone. They are close enough that you can do that, even if you are camping in one park. Make sure you check with the rangers at Old Faithful. We were lucky enough to see Beehive go off, which is bigger than Old Faithful.
Sunrise in the Tetons was the best part of our vacation. You have to get up early, but we saw moose, elk, bear, and pronghorns. Not to mention the light on the mountains, absolutely beautiful.
If you want to see some of our pictures of our trip you can at:
http://www.eburkedesign.com/AGW3/ArokGoesWestIII/Welcome.html
Ten days is more than enough in Yellowstone. You should also try to spend some time in the Tetons. If you can nab a spot for the last two days at Colter Bay you may want to consider that.
We are going to Yellowstone in two weeks! Make sure you spend a day driving and hiking along the Beartooth Highway. Break the two loops of Yellowstone into modest daily excursions and you will have a blast. Get an early start each day to beat the crowds and see more wildlife.
We will be at Grant Village Aug 24-27--look for the Sea Pine!
Family that loves to camp 30 days a year! Two kids, 13 and 9
We definitly plan on visiting the Tetons pobably ending the day in Jackson for dinner While sightseeing is a priority I'd like for Katie to to interact with some of the locals. All she knows is NE, hopefully she can bring something back with her, broadin her horizons. I'd love to visit Glacier but the extra 400 miles might be tough. Maybe next summer. Personally I'd enjoy that snake river rafting trip. Four days and counting!
If you are in Jackson, and like beer, grab a bite at the Snake River Brewery, they have a section for families to dine in. In addition to very good beer the food was tasty. Otherwise Bubba's Barbeque was good too.
Just be prepared for crazy drivers who don't pay attention to where they are going. That little town was worse than rush hour here in MN!