We've driven that route several times. Here's a few things to see going W to E.
1. Its a pretty drive up the Clearwater River, and over Lolo pass. We've camped on the river in an RV Park in Orofino, ID.
2. Big Hole National Battlefield near Wisdom, MT is a great historical site.
3. Bannack SP in Montana is an amazing and well preserved western ghost town. The CG there is very, very nice. We really love this place. We were there when it first opened after major flooding a few years ago. The governor was there with period music and costumes performed by well informed volunteers and staff.
4. Virginia City, MT, another nice ghost town, but not quite as authentic as Bannack. I have a relative that was a sheriff there before MT became a state.
5. Earthquake Lake Visitor's Center is worth a visit.
6. West Yellowstone is an interesting tourist trap just outside YNP. Grizzly RV Park is very nice. You can hear wolves from the Grizzly Recovery Center.
