What is the most scenic driving route across the US from Washington,
DC to Seattle, WA?  I am driving alone, sometime in late September,
early October, and will have 8-10 days to do it. I do not want to
spend all my time on fast interstate highways where I'll see nothing,
but I also don't want to drive on more "interesting historical routes
(like Rt. 66) just to be on them if it doesn't take me through an
interesting town or beautiful scenery.  I know that I-40, I-50 and
I-80 run east to west.  I also know there is a route that runs up
north alone the Canadian border.  I am looking for the best overall
route, using any combination of these roads and/or others. I wouldn't
mind seeing the Grand Canyon on my way if it can be easily worked into
a route.  Thanks!

I-90 runs nearer to the Canadian border sometimes coming south at some
places like Chicago

If you have one nearby, I'd suggest going to a AAA store and picking
up some maps. When you take a close look at the state maps (and
possibly the one for the continguous US), you'll see dots running
beside some of the highways--this is their symbol for scenic thruways
and they've never steered me wrong.