Heads up on the solar eclipse... August 21, 2017
You can google the path... it's crossing the continent and anything along it's path is booked already.
hwy 2 across Montana takes you around the bottom part of Glacier NP. I've known some who have driven right past without realizing that. EAST GLACIER Park Lodge has the grandest lodge. Google that and you'll see the interior is something you'll want to see.
If you cross the Columbia River (between George and Vantage) on I-90 stop and use the overlook. There's a metal horse sculpture on the ridge. Google
"Grandpa Cuts Loose the Ponies".
All of your sight seeing depends on what fires are burning where and how much smoke and which way the wind is blowing.
If for some reason you want to head south from Glacier NP... from Missoula you can take Lolo Pass into Orofino (PINK HOUSE CG is a few miles outside the west edge of town)... pick up I-84 to get into the Columbia Gorge. Multnomah falls will be just a trickle so you won't see it unless you stop there. You won't see it as you drive by.
Google VISTA HOUSE overlook... but you won't get up to it towing anything.
Silver Falls State Park in Oregon... has wonderful waterfalls but you need to plan ahead. it's an all day flat hike but you do a steep climb in and out.
Best BLM campground is near Mill City, Oregon .. Fishermen's Bend. (Between Salem OR and Bend OR)
