I've started plotting and planning this. The basic idea is for a bunch of us to meet in one place, load people and things into cars, and drive a caravan across to Spokane.
Right now I'm looking at two different routes, from the two big PNW travel hubs, Seattle and Portland. I'm looking at distance, attractions and facilities on the way, and other interesting things along the way. Once I have those mapped out, I'll put up a poll to chose between them.
Some quickie FAQ:
1) This would be a full day trip. Straight driving from either Portland or Seattle runs about 4-5 hours. I dislike driving straight through, and it's impractical with a caravan, so we'd be making regular stops.
2) We'll stay together. If you're the kind of person who doesn't want to be held up by others, or drive only 70, this might not be the adventure for you.
3) There's Stuff to Do along the way, and I want to plan time in for those.
4) There will be some financial outlay. Some of that will depend on what we come up with as far as vehicles, gas, food. No one would be turned away for lack of funds, though! (I might just put them to work...)
5) You will be responsible for getting to the launch pad in Portland or Seattle. I highly reccomend the Amtrak Cascade train for any travel between Vancouver BC and Eugene OR.