Best Casinos in South Dakota Ranked It's no secret that South Dakota loves its gambling. Moreover, tourists are flocking to the Mount Rushmore state more than ever before to visit our casinos. There are currently 22 commercial casinos in the state of South Dakota, but which ones come out on top? Check out this list of the very best casinos in the state. According to Trip Advisor, here are the current rankings: Get our free mobile app 10) Royal River Casino, Flandreau: The only non-Deadwood casino to make the list! 9) The Depot Motherlode Gaming Saloon, Deadwood: Located in the heart of the town, this casino also has a number of restaurants and bars nearby.