US hwy 12 from Lewiston, ID to Missoula, MT

Do it!

Everything Islandman said! That trek was usually our route of choice when heading to Kalispell to visit family. Usually would stop at either Wilderness Gateway of Powell for a night or two. Wilderness if the weather was cool or Powell if warm (hook ups to run the A/C). Enjoy the drive, it is beautiful!

As others have noted, take your time and enjoy the trip. Stop every once in awhile and take a walk down to the Lochsa or Middle Fork Clearwater Rivers, water is very clear and the vegetation is colorful. Stop at DeVoto Memorial Cedar Grove, Indian Post Office, USFS Visitor Center on Lolo Pass and other places that suit your fancy. Nice campground at Wilderness Gateway, good sites and easy to drive around in. Stop at the USFS office in Orofino and get more info on the things to do and places to see along the route. This road is probably our most favorite drive anywhere, have been driving it off and on for over fifty years.

Spectacular trip and no problem with your rig.

We have pulled our 28 and 35 foot TTs through there and not had any problems. It is a great scenic route that I hope to travel again this summer in our MH.

Very scenic. Lot's of bicycle riders, they have buses carrying them to the top of passes and they riding down. You'll follow a river most of the way. Saw a number of kayakers in it.

Ooooo,really fun run. Take it slow and easy and east to west is pretty steady uphill. We stayed at Lochsa and there is a great campground there with several 100' pull thrus and water and electric in about 1/2 the cg.
Side note; It's about 13 miles from Lolo pass to this place and it Lewis and Clark 12-13 days to make the trip.

They took the mega loads from Lewiston to the Canadian Tar Sands project on this highway. If those made it, I can't imagine that you will have a problem. Just take it slow...and be sure you use the turnouts to let others pass you when they need to. It is a beautiful drive, mostly right on the river. Lots of Lewis and Clark history in this area, too.

Went that way on my motorcycle when I was on my retirement trip in 2008. Really enjoyed it. Would love to be able to do it again.

Great scenic drive!