I know understand why a significant portions of centrally placed US states are referred to as the 'plain states'. But they are not plain in the sense of being simple, but rather that they are mostly plains. Although, you could argue, that from a geographic point of view, they are simple. Their topography are mostly flat.
Driving from Columbus to Yellowstone is a long drive. And the lack of changes in scenery makes it all the longer. It is just fields and fields for hundreds of kilometres on end. So I took the motorway from Columbus through these flatter states. Country roads would not prove interesting. Or rather, not interesting enough.
But I did manage to find one spot I wanted to visit on my way through these plains: Elk Horn, Iowa. This town has a large group of descendents of Danish immigrants, that they pride themselves on, and presenting Danish culture to an American audience.
I should note, though, that while their history of Danish America was in of particular interest to me, their take on Danish cuisine is off. There are a lot American oddities intertwined with it, and some of it has origins in neighbouring countries, like Germany or Sweden. But it was fun to visit, and I slightly regret only having such a short time to visit it, before I had to head out to Rapid City in South Dakota.
When you get this far west in the US, it becomes more and more clear that the borders between states are purely drawn based on longitude and latitude with no regard for the physical terrain. I understand why it is less important when the place is flat, but once the Rockies begin to show themselves, the nature of the borders feel far more arbitrary. But considering these lands were divided before they were properly explored, I suppose it made sense.
In their defence, we still have odd borders in Europe here and there. And we have had centuries to fix them. And I know it is not for a lack of trying, just consider Napoleon and Hitler.