I haven't forgotten about posting more about my recent trip; I've just been swamped. Here's the first bit; I hope to have a bunch more.
On Interstate 90/94, a few miles eat of where 90 and 94 split at Tomah, at exit 55, there is a rock formation called Castle Rock and an interstate wayside where you can stop and view it. I highly recommend doing so to anyone driving along that highway, if you pass by during the day and you can spare a few minutes. It's quite a rock.