What month are you guys thinking about going out there? IIRC, Sturgis is around Aug 5-12 this year. You'll see a lot of, um, slower bikes than your Streetfighters out there...
When I went over some of this route a few years ago, I was surprised at how many bikes there were out West. It turned out that I unknowingly went during bike week. I did meet some cool people when I rolled into Sturgis with CA plates. I even scored a free breakfast out of it when I said I was riding to Boston and back. The guys just had to hear about my route. I joined a cruise through the Black Hills to Mt. Rushmore. The Black Hills were a highlight of my XC trip. For you, this is probable a bit too far east. Maybe next time. BTW, my bike was the fastest bike out there through the Black Hills. I must have passes 50-100 bikes at a time, when allowed. I was on a F650GS Dakar. I can't imagine how many you guys could pass on the ducks...
It's gonna be a great trip!