Crud, I’m not familiar with that area at all. I’ll tell you what I would plan, knowing the lower section of Oahe.
We tossed a lot of jig and minnows with twister tails. My favorite colors were motor oil, black with chartreuse tail, electric blue and good ol’ chartreuse. We would also lindy rig with minnows, leeches or crawlers early on at times. It depended on how deep you were finding the fish, but most often it was jig and minnows for the most part.
I wish I could be of more help to you. I know this, it’s beautiful country up there so enjoy the trip and give us a report when you get back. Good Luck!!