Leave Saint Paul and head west on Hwy 212. A good scenic stop to make about 2 hours in is Alexander Ramsey Park in Redwood Falls. It has a beautiful waterfall and a wonderful park.
From there, keep heading west to get to your first campsite at the Lake Thompson Recreation Area in Lake Preston, SD. This is a nice quiet campsite near a lake. If you want to take a little side trip, visit the nearby Laura Ingalls Wilder Homestead in Desmet.
When you are back on the road, continue heading west to Mitchell, SD to check out the unique and impressive Corn Palace.
Continue on you journey and stop in Chamberlain, SD where they have a wonderful rest stop with a Lewis and Clark Interpretive Center. There you can climb aboard a re-creation of the expedition’s 55-foot keelboat, which sits both inside and outside the center and appears to traverse a 30-foot wall of windows overlooking the Missouri River. Exhibits inside the center depict items the explorers brought on their journey and show examples of the wildlife the Corps encountered.
Your next stop with be the Bad Lands/White River KOA campground in Interior, SD. This will be a good base camp to explore the Bad Lands. Badlands Loop Road (U.S. Hwy 240), is a scenic byway that cuts directly through the middle of the north unit surrounded by a labyrinth of beautiful landscapes. Sage Creek Rim Road (Route 590) is a gravel road that takes you along the northern rim of the Badlands Wilderness Area. The dirt road hugs the dramatic drop off separating the South Dakota prairie from the alien landscape below. Keep an eye out for some adorable prairie dogs!
There are also lots of other hiking/sight-seeing options if you would like to explore the park that way.
Another great place to stop in the Badlands area is nearby Wall, SD. Stop by the No. 1 Roadside Attraction in America—Wall Drug Store. Other great places to see in the area are Dinosaur Hill, Bear Country and Reptile Gardens.
Journey a bit farther west to your next campground in Rapid City, SD—Rushmore Shadows Resort. This will be your basecamp for exploring the Mount Rushmore area. Rapid City itself is a great little city to explore. They have an awesome square in the city that has a stage for music, a large open grassy area, and a splash pad for kids. The square is also surrounded with restaurants and shops.
Head down to Custer State Park and enjoy a scenic drive on the Wildlife Loop. The best scenic drive in the area is the Iron Mountain Road. This winding road runs between Mount Rushmore National Memorial and the junction of US 16A and SD 36 in Custer State Park. Along the highway, visitors will find wildfire exhibits, pigtail bridges, magnificent Black Hills scenery, and tunnels that frame Mount Rushmore. Winding drives throughout the park are best when enjoyed at a slower pace. When making plans, please allow ample time to travel at a safe speed—generally 25 miles per hour or slower. Expect travel time of about 60 minutes from the State Game Lodge to Mount Rushmore.
Other things to do in the area : Jewel Cave, Crazy Horse, Sylvan Lake, Needles Highway. Drive up Mt. Coolidge, Wind Cave, Mammoth Site. Take a drive through Spear Fish Canyon. Check out the DC Booth Fish Hatchery. The kids will love a stop at Storybook Island.
From there you will head to your last campsite at Palisades State Park. Split Rock Creek, which flows through the park, is lined with Sioux quartzite formations varying from shelves several feet above the water to 50-foot vertical cliffs. It’s a very beautiful park and highly recommended.
From here you can journey back to Saint Paul which is about a 3 1/2 hour drive.