Hwy 12 runs along the river and there are 77 miles of curves. There is one 'climb' - Lolo Pass at 5235' EL. You will have 5% grade down for 4 miles. It's not bad.
This road is popular with RVers and bikers and the two don't mix well. Be alert. It's a beautiful drive.
From Lewiston you'll have a climb for 6 miles. No problem. Uphill isn't bad... just slow. It's southbound downhill that's a doozy!
Full-Timed for 16 Years
.... Back in S&B Again
Traveled 8 yr in a 40' 2004 Newmar Dutch Star Motorhome
& 8 yr in a 33' Travel Supreme 5th Wheel