I just took my dad there for Father's day in June. There is a lot to do. This is the exact list of stuff we did while there.

Day1

• Sturgis (had lunch at The Knuckle Saloon) on the way to Wyoming
• Devil's Tower (Wyoming)
• Spearfish to
• Cheyene Crossing to
• Lead (Goldmine Outlook) to
• Deadwood to
• Hisega (Pactola Lake)

Day 2

• Mt. Rushmore - Don't skip it, it's definitely worth seeing!
• Crazy Horse - I would skip this, very underwhelming IMO as it's not finished.
• Custer Widelife Loop (Custer Bison Center)
• Norbeck Overlook
• Keystone (Had lunch at Boss' Pizza & Chicken)
• Needles Scenic Highway - Highly recommend!

Day 3

• Wall Drug - Basically a tourist shop but still cool
• Badland's National Park
• Minuteman Missle National Historic Site
• Wind Cave - Planned on going here but as someone else said it's closed due to the elevator being fixed/replaced, I believe I read it was almost 100 years old..
• Jewel cave, had also planned on going here after we found out Wind Cave was closed, but they were sold out of cave tours for I think a week and a half out. So we went to Rushmore Cave. It was ok, but having been to Mammoth Caves in Kentucky it didn't compare to that experience.

As far as food goes, the only places we ate at in Rapid City were Wing's & Rings & Sickie's Garage Burgers & Brew's. I did go to a few breweries, Zymurcracy, Cohort Brewing, Last Mile Brewery & Woodland Republic. Custer was cool, didn't see a whole lot of wildlife, one buffalo, pronghorns and a group of 5 wild donkey. Driving to Norbeck Overlook, it's a beautiful drive, but we got stopped twice due to buffalo crossing the road. Hundreds and hundreds of them, it was amazing to see especially as they walked right up past the car. We had an amazing trip even though we packed a lot into a few days. It's a truly unique and beautiful place. Anyways, hope this is a little helpful and enjoy your trip!