On Thursday some areas saw wind gusts up to 70 miles per hour.
That's strong enough to topple trees and power poles. Downed lines have left thousands without power in Rapid City, Deadwood and Custer.
Outages have closed down at least one school district, along with county offices in Pennington County.
Black Hills power says in most places the electricity is back on. But the Needles Highway isn't expected to open back up until Friday, due to falling trees. State officials say it's especially bad in areas hit hard by pine beetles.
The winds are also causing trouble on the road. We’ve had reports of several semis tipping over on its side.