Restaurant : at Sylvan lake lodge and Legion lake lodge, both restaurants are family friendly.
A diner at the game lodge, in the historic dining room-not in the big room could be a nice experience.

Hikes : Doors, window and notch in the east part of badlands national park, saddle pass also in badlands;
In Custer, Little Devil's tower is nice but also Harney peaks from Sylvan lake.

In Keystone, the alpine slide has been apprecied by my teens 2 years ago...

In Custer, the museum in town is
small, but interesting, for the kids+++.

Try to get the schedule at the Blackhills playhouse : perhaps there will be a musical during your stay.

Even if it's a turist trap, Walls on the way to or from Badlands worth the visit with kids, explaining what it was for the travellers in the '50 to '70.

To see wildlife, drive early and/or in the late afternoon the wild life loop in Custer Park.

In rapid City, the journey musuem is a must and also the Prairie Edge
as shop of indian artifact.
Reptile garden is often misapprecied by the "intellectuals", but for 11 years old child it's a nice half day with reptiles, but also a prairie dog town and some nice bird's show.
Erik

Don't forget to bring apples for the donkeys in Custer park.Paul

We just did the Black Hills with kids 5 and 8 (along with ND and MN) - you're hitting all the highlights for sure (if you can get them into the jr. paleo dig @ Mammoth Site - do. It's hands on fun). Do the Jr. Ranger program @ Rushmore. We skipped the jeep tour and drove the Wildlife Loop on our own - kids got *plenty* of viewing - ask where the bison heard is when you pay your entrance fee. We fed the wild (begging!) burros carrots and apples. In the Badlands, seek out the Big Pig Dig - it's a smallish dig located off the main road...but staffed with a ranger and interning paleontologists. Our kids got a 45 minute one on one "tour". Hike Sylvan Lake - it's just beyond the beautiful lodge - it is stunning and an easy loop. Easily a highlight for us parents. We liked Hill City - smallish and nostalgic - close to Crazy Horse for an easy lunch or light dinner. If your schedule allows and you're in the area (coming across SD from the East), I'd recommend the Ingalls Homestead. Our kids were in love with that place - and we slept in covered wagons!

Enjoy!

Another cool Black Hills "don't miss" is Needles Highway.

FYI, the wild burros are neat, but just be aware that they are pretty aggressive when you bring out the food!

My twins were ten when we took them to SD and what they loved most was climbing all the rocks. They loved climbing the hills at the Badlands, the rocks at Mt. Rushmore and Devil's Tower. We rented paddle boats and went swimming at Sylvan Lake. That was really fun. We did a chuckwagon dinner in Custer State park. They give you cowboy hats and you sing silly songs as you ride in the wagon to the dinner location. The best food we had was in Custer at the Sage Creek Grill.

Great recommendations all around!
Our favorite hike is the hike up Harney Peak, starting at Sylvan Lake. The hike is about 7 miles RT and is at an easy-moderate level. (My daughter hiked it when she was 8 y.o.) At the top is the old stone fire lookout and great views all over the Black Hills. It's a very scenic hike which your family should enjoy.
If you get a morning start, you could do the hike, have a picnic lunch (or lunch at the Sylvan Lodge) followed by paddleboat rides on the lake. That would make for a nice day's adventure.

On a solo drive through Custer in '91, I pulled off the road for a short hike (I think it even said "Fire Tower Rd") and after a short while was at the top of a ridge where there really was a fire tower that said, "C'mon up!". What a treat for me as well as the woman ranger on duty. We shared a long conversation about her work and the surrounding forests. One of my life highlights.

When we went a few years back, friends of ours recommended that we do the Jeep tour. We were really glad we took their advice. My brother is taking his kids in a couple of weeks and I recommended it to him.

We stayed in Custer State Park. And we saw more wildlife just driving around the park than we've seen on any other trip, before or since. But, even so, I feel the Jeep tour was well worth it. Besides getting out on roads we wouldn't have taken, the drivers communicate with each other and know where the buffalo herds are, etc.

We also really enjoyed talking to the driver. Many of the guys who do those tours are Florida or Arizona retirees who drive their RVs north and work in state or national parks to escape the summer heat. Most of them have wives who work in the shops in the park. My husband and I thought it sounded like a great way to spend summers! (If, after getting our second kid through college, we're ever actually able to afford to retire! )

http://www.gwtc.net/~iram/

Black Hills Wild Horse Sanctuary is on my list of must see's. It's been quite a few years since I've been there but they have done some amazing work and the area alone is georgous.

It's been years since I lived in Rapid City, but I was around 5 and still remember Reptile Gardens, Dinosaur Mountain, and The Needles (get out and look for rose quartz and mica). Also, Deadwood, Lead, and the badlands...

topping

Thanks everyone. This is great advice. Any other restaurant suggestions? I'll try to write a TR when we return.

All the above, plus we enjoyed Bear Country USA, in Rapid City (even in a thunderstorm!)
Have a great trip!

kansasmom...
I wanted to take our two 7 YO grandson's to this same area this summer, but it didn't work out and we went to Arkansas instead. From SE KS, I didn't think this would be a bad drive with two kids. Can't wait to see a trip report when you get back. Have a great time! I'm jealous!!!

In Rapid City, the Corn Exchange is an excellent restaurant.
In Spearfish, the Latchstring restaurant ath the mooth of spearfish canyon worth the detour(a whole day could be : Keystone/Spearfish canyon : hikes/waterfalls : 2-3 different easy hikes/ lunch at the restaurant/Heritage center in Spearfish-very impressive museum of the west/Deadwood and back to keystone.
Erik

I recommend a day trip to Devil's Tower and maybe a stop at Wall Drug...if you are going all the way to South Dakota, a stop at the tackiest place on Earth is probably necessary. Your kids will probably be amused with the amount of Wall Drug billboards too...I know mine were when we drove out there!