Totally stumped till I looked up the name in clue #7.
And I say that as someone who has driven through, and helped someone look at a house in DeSmet, South Dakota.
I think I would have been in the same boat, if our places were reversed. I didn’t mean for it to be exceptionally difficult, but I can see why it might be. (I only get the DeSmet reference because I researched the character in post #7.)