the lighting was cool and there is some non-strenuous walking tours. Hit Custer State Park for sure, I could spend a whole week in that place. Make sure you see some caves as well, some are national monument type of caves, like Timp, and others are not as nice, and more commercial, but fun for the family. We did Rushmore Cave, which has a zipline and 3d zombie game/theater. Interesting combo, my kids were 13 and 10.

We stayed in Custer and enjoyed it. Like a less busy Jackson Hole. Keystone is an armpit.