We are planning a mini Black Hills trip in 2019. We are planning to stay in a cabin right outside of Keystone, SD as a home base for activities. Besides Mt. Rushmore, Crazy Horse, and the Badlands, we are planning to spend some time at Custer State Park. They have a large buffalo herd there and burros that you can feed carrots too. We want to hit the wildlife loop at the park at dusk on one of our days. The park also has an area called Sylvan Lake that is a nice spot for a picnic I hear and some very scenic roads: One is called the Needles Highway and one is called Iron Mountain Road. For Iron Mountain Road the recommendation is to take this South to North as at the end it frames Mt. Rushmore. We will be hitting these places on our trip too.
We aren't really into caves, so aren't doing these, but there are two caves that are part of the national park system right in the area too that have pretty grounds and wildlife around also I hear. One is the Jewell Cave National Monument and the other is Wind Cave National Park. These are very popular for people to include on a vacation itinerary in the area.
Our time is limited, so we aren't doing this either, but there is an area that people say is stunning for doing family friendly hiking an hour or so north of Keystone called Spearfish.
Anyway, those are a few more options, all within an hour or so of Mt. Rushmore. There have been other suggestions that are a little farther away too, so if you are looking for more I can mention what others told me about those. We were planning on staying at one place the whole time and didn't want to drive all that far in any one day, so mostly considered the above options and have a tentative itinerary with our top picks. We'll be visiting some friends who live in Stugis one evening of our stay also.Edited: 28 December 2017, 04:49
Kathy has given a very good overview. Custer State Park is a must see, as are the caves, as long as no one is opposed to being underground. Since you visited Bear Country last time, there's Reptile Gardens this time. you also have the attractions of the northern hills, including Deadwood, Spearfish Canyon, and Devil's Tower. Chapel in the Hills is a lovely Norwegian structure church that can be visited near Rapid City. If you order a travel planner from travelsouthdakota.com, you will get a great overview of the area.
Have a good trip!
Not sure where you are coming from - we drove from MI and stopped at the following
Sioux Falls and enjoyed the falls
Custer Park - could easily spend a day there or even two. We had a great time but ran out of time.
Mammoth Site - was ok.
Needles Highway - worth the drive
Deadwood - a day was good for us. Enjoyed walking around and stopping to have a drink and listen to music
Devil's Tower - enjoyed a lot!