Originally Posted by Zipper 104

I'd suggest staying on the east side of Glacier National Park by way of Waterton Lakes as you leave AB and down to Missoula. From there you head west out of Missoula and go the Lolo Pass (?) across into Idaho and down through the Sawtooth Nat'l Forest through Salmon, Ketchum (Sun Valley) to Twin Falls. The road into Idaho from the top of the pass west of Missoula is a fantastic stretch of fast, downhill sweepers. The peak just at the top had a massive forest fire back about 2004 which is an unreal sight.
The route is almost devoid of traffic. I cannot say it's an improvement over your proposed route. I can just speak for how awesome this route is, and most of your northerly route through WA, thru Spokane, is a big yawn.
It gets good again on your route from there down to Boise.

I'm thinking I might be too late with this.

Have a good trip.....and remember. The WA State Patrol has eyes in the sky. Don't ask me how I know.

104