7 days of travel minus three days in Fargo. That leaves 4 days, of which one is to get from Fargo to Milwaukee, and one to get from Mt. Rushmore to Fargo (530 miles). You have two days to get to Mr. Rushmore; that's just enough to do 800+ miles (distances established by using Google map).

I'm sorry I must have said that wrong, 5-7 days are for the South Dakota part of the trip and then 3 additional days for the wedding in Fargo. Days are pretty flexible and can be based on how much there is to do in South Dakota.

Thanks for any ideas!!

In the South Dakota portion of your trip, don't miss tghe Badlands Nat. Park and Wind Cave. The Jewel Cave and Crasy Horse monuments are worthwhile if you have time. And, the kids might enjoy the very touristy Wall Drug in Wall, SD and the equally touristy Corn Palace in Mitchell, SD. Also , Deadwood and mining attractions in and near Lead.
Have always camped when visiting so can't help with where to stay.

I-90 Westbound is probably your best bet to get across Minnesota and South Dakota. In Austin, MN there is the Spam Museum which is kitschy and fun (more so than you might expect!).

In South Dakota, Sioux Falls has Falls Park which is a nice break from the road with its' rose quartz stone and multiple waterfalls. There is Sertoma Butterfly House where you can walk thru a room with hundreds of butterflies. Depending on time, there's also a nice zoo (Great Plains Zoo) and a big outdoor waterpark (Wild Water West).

Across South Dakota, The Corn Palace in Mitchell is worth a quick stop as it's interesting to see how it's decorated. The Lewis & Clark Welcome Center on the Missouri River has an interesting exhibit and fantastic views of "west river." Just across the bridge, Al's Oasis is a nice stop for pie and 5 cent coffee. They also have a decent grocery store if you need supplies.

Murdo has the Pioneer Auto Show which my family really enjoyed. It's more than just cars and is a nice break from the road for a couple hours.

If you have time a side trip thru Badlands National Park would be easy using the loop road that takes you thru most of the park and then back up to Wall. Wall of course is home to the famous Wall Drug.

As far as in the Hills, Keystone is the closest town to Mt. Rushmore and only a mile or so down the road. It's pretty busy and touristy so take that into account. Hill City would also be an option as it's not far and would also make a good central base for exploring.

There is so much to see and do in the Hills, but I can give you what are now my family's favorites after many trips out there...
-Custer State Park for animals and scenic drives
-Mt. Rushmore early morning for pictures and late evening for the lighting ceremony
-Reptile Gardens & Bear Country USA in Rapid City(although if I could only pick one it would be Reptile Gardens)
-Black Hills Institute in Hill City
-Dinosaur Park & Skyline Drive in Rapid City
-Ellsworth Air Force Base in Rapid City
-South Dakota School of Mines & Technology Museum in Rapid City
-Jewel Cave west of Custer
-Ken's Minerals and the Purple Pie Place in Custer
-Spearfish Canyon scenic drive
-Devil's Tower National Park day trip
-The Mammoth Site in Hot Springs

These are most of our favorites, as you can see you'll have no shortage of things to do out there!

Wow! Thank you so much for all the fantastic ideas & details!! I am really excited to plan this trip! Thanks!!

I would go to www.travelsd.com and request a free vacation guide. You will find lots of info in there and I think you will enjoy looking through the guide. They have a great map of The Black Hills and also other activity ideas like: President's Alpine Slide in Keystone, Cosmos Mystery Tour near Keystone, etc. The map has great loop drives. For best views, I would do Needles Hwy North to South (don't miss Sylvan Lake) and Iron Mountain Road South to North (Mt. Rushmore is framed through the tunnels). When/if you do the Wildlife Loop in Custer State Park, don't forget a bag of carrots or apples for the wild burros (last time we could have used TWO bags of carrots, lol). They're usually on/near the road & will come up to your car, begging. Your kids will love their time with the burros! We usually stay in Custer but I think, with children, Keystone would be the best choice for you to stay, as there are lots of activities in/near Keystone and it's central to other things/areas. We love The Black Hills and have been there twice: once in 2010 and once in 2012. Have fun looking through the guide and have a great trip!

Mt. Rushmore is only going to take a few hours to visit (if that). I would not base my lodging decision on proximity to Mt Rushmore. Instead, figure out what else you want to see/do in that area and find convenient lodging for those activities.

Also, see if you can drive through Theodore Roosevelt NP in ND on your way to Fargo. Definitely worthy of some time. Just don't count on finding lodging close by, you might have to drive to Bismarck for the overnight.

Rapid City is a good place to base yourself out of. There are many different places to stay there that fit all price ranges and driving to the numerous attractions is easy even Devil's Tower in Wy. The Badlands National Park and Rushmore are must. Kids like the 1880 Steam Train out of Hill City and that gives you a great way to see the scenery of the Black Hills. You can board this in Keystone too. Needles Highway, a mountainous 2 lane road not a "highway" , has tunnels that you can see Mt. Rushmore through in several locations and the scenery is amazing. Pierre, the state capital is approx. 30 miles off I-90 off exit 212. It is about mid way through the state. Taking time to see it is worthwhile. Our capital is open to the public and very beautiful. There are many sculptures on the grounds that surround Capital Lake and a nice walking path. The town is also home of Oahe Dam. This was the largest earth rolled dam in the world until China built one. It is fun to see and drive across. Lake Oahe is an enourmous lake that goes all the way to the North Dakota border. Taking the backroads, and not always the interstate, will allow you to see old pioneer homesteads, fields of sunflowers, grazing wildlife and lots of great scenery. What ever you do in SD make sure to talk to it's citizens. They are the friendliest folks you will meet.

Agree on taking time to see Theodore Roosevelt National Park in ND, and agree that lodging might be scarce around Medora. Rapid City is a good base, though I liked Spearfish, a little farther north but a little less congested. Spearfish might be too far away from Badlands and Custer area to suit you, though.

For TR National Park you could easily stay in nearby Dickinson