Ozz,
I've gathered you're an avid cyclist from some of your posts. You should check this link out if you can make this stop into your country tour.
There's lots of history and they've turned this former train route into a bike path (I'd recommend the downhill direction). It traverses more tunnels and trellis bridges in the shortest distance than I've ever heard of in an attempt to maintain a consistent grade. I regret not having completed this but you can do this. I think you'd enjoy it. DW and I drove down much of this area (not where it's bikes only), but I understand you can bike ride from Taft (Exit 5, I-90) all the way to Pearson, ID.
http://friendsofcdatrails.org/Hiawatha/index.html