Nice place to be. There are a number of places to go to see stuff.
In Watertown there is the Terry Redlin art museum. He was (passed in April '16) a local artist whose wildlife and outdoor art works are beautiful. All of his original works are there with the exception of one.
Terry Redlin You will not believe this museum.
Then there is the
Corn Palace in Mitchell. It is kinda a TT (tourist trap) but it is pretty neat to see.
There is the state capitol in Pierre. It is not pronounced like the French guy but is pronounced "Peer" just so you won't sound like an outsider. Take the tour, it is very interesting. Maybe you can find the one missing blue tile
State CapitolLast but not least is Cabela's in Mitchell
Cabelas