Who runs guided night experiences here
Both operators below are run by My XO Adventures, which also built and pays for this site. That is worth knowing before reading any recommendation on it.
My XO Adventures
Private guided tours across Badlands National Park, the Black Hills and Devils Tower. One group per booking, never shared. The night and low-light itineraries are the Badlands sunset and night sky adventure, the golden hour tour, the Mount Rushmore illumination tour, and a sunrise tour of the park.
Badlands Tour Company
Tours in and around Badlands National Park.
Not on this list
Plenty of people run night sky experiences in this region, and a list of two is not a survey of them. The Badlands Astronomy Festival brings in telescopes and astronomers from several organizations every July, and the festival page names them.
Any operator running night sky, astrophotography or sunset trips in the Badlands, the Black Hills or Devils Tower is welcome here, including direct competitors of the two above. Get in touch and the listing is free. There is no fee for being listed and no fee for being listed higher, because the moment there is, this page stops being worth reading.