We live 3 hours closer to Custer State Park than Elkhart is. We live off I-90, 20 minutes west of Chicago. Taking the route recommended by Phoenix is longer in miles but avoids lots of tolls or lots of traffic. And that route is least complicated.
When we travel out west on I-90 to the Black Hills area, actually throughout our travels everywhere, we stay overnight in a Walmart parking lot. If one is not found, our second choice is overnight parking in a rest area. We are never doing that alone. There are always other RVs...strength and safety in numbers. It's legal too. Walmart welcomes it in most their stores outside huge cities, or tourism towns.
Don't just run direct to Custer State Park. Spend your second night at
Badlands National Park. While there, visit
Wall Drug and
Minuteman Missile National Historic Site. When we were at the missile site, the visitor center was a double-wide trailer. I see on their website, the visitor center is so much more now. Get reservations to see the off-site Delta 01 and 09 (underground command center and silo with rocket), but if there are non available, sign up there as a stand-by.
My favorite hike at Badlands is the notch trail at sunrise or sunset, but I see the ladder is being worked on, closing the trail this season. Double-check at the visitor center for they might have reopened it and did not update their website. The notch trail is short and fairly easy as long as you can use the easy-to-use cabled ladder as shown.
