Tomorrow you'll have more mountains (and trees!) from Pendleton to just east of Baker.

Stop at the various overlooks and the Oregon Trail historical markers. As said before, be sure to top at the Oregon Trail Interpretive Center ... its northeast of Baker .. It's on Highway 86 a mile or two east of the freeway ... I think its exit 302 that you take (exit numbers are always mileage indications from the highway start.)

And you may want to stop briefly (lunch?) in downtown Baker .. it has quite a few historical buildings from the nearby mini-gold rush era.

Once you leave Oregon it will get quite flat and dry all the way to Twin Falls ... like the country you went through west of Pendleton.

The only thing of interest I can think of in that stretch is maybe drive through downtown Boise ... its heavily treed (a good break from the golden dry country) and its the Idaho state capitol

PS
At Twin Falls one thing that may be of interest is Shoshone Falls on the Snake River ... it's almost downtown, about a mile or so east of where the main north/south road into Twin Falls from the freeway crosses the Snake River

Northeast of Twin Falls is Craters of the Moon National Monument - lots of unusual rock formations and old lava flows. I'll let you decide whether its worth your time ...not my cup of tea but many like it.

When you get towards Idaho Falls you should check on the route to take into Yellowstone Park. Most entrances, and much of the park is unaffected, but a forest fire has, for the time being, closed the south entrance (the road between Yellowstone and Grand Teton. Today's update is at http://inciweb.nwcg.gov/incident/article/4940/33111/

ChantaIF:
Hurray! All the entrances to Yellowstone have been reopened today, although you will likely experience some smoke. See http://inciweb.nwcg.gov/incident/article/4940/33208/

At a few locations there are places being set up to observe one of the fires where fire information personnel will be available to answer questions. This might be a very interesting opportunity for you to stop for a few minutes if your trip takes you nearby. It appears they are along the combined US 20 & 191 between West Yellowstone (the west entrance) and the junction with US 89 inside the park.

If you enjoy reading in English, a great book to read is "The Big Burn: Teddy Roosevelt and the Fire that Saved America" by Timothy Egan. It's about a massive forest fire in 1910 that consumed many towns. It resulted in the creation of the national forest service. It's an exciting read focusing on many of the people involved and their survival.

Today we drove to Twin Falls. Followed your advise and stopped at the Oregon trail interpretive center which was very interesting.
In Twin Falls stopped at the visitor centre for the view at the bridge and the river and also went to the Shoshone Falls.
Tomorrow the last day to drive a lot of Miles because we will stay in Yellowstone for 1,5 weeks.
I also saw that the south entrance is open again. Hope that there won't be more spread of the fires that are still there but the fires are quite natural in Yellowstone although i'm ofcourse not used to it. But with these temperatures and dry land I can imagine a Fire is started very fast. But yes, it may be interesting to stop and observe and learn more About the fires.

Maybe we will stop first at the Idaho Falls of other place we see allong our route before arriving in Yellowstone.

Chantal, regarding SOME of the stark difference in landscape between Western Washington and Eastern Washington, you can read at glaciallakemissoula.org about the ice age flooding which carved the Columbia Gorge and which washed much of the lush topsoil from Eastern Washington through the gorge, before dumping lots of it into Western Oregon.

(even though you may not have viewed the bullseye in terms of what is {the middle of} Eastern Washington landscape )


And thanks for stopping in here to let us know that you have taken some of the paths mentioned here.

Today drove to West Yellowstone and did a stop at craters of the moon. It was very interesting to learn what happened and we were really impressed.
Luckely we didn't had any delays on the route to West Yellowstone but we could see the smoke of the fires when entering West Yellowstone.
Will do a check up on the fires tomorrow.

Thank you all for your help on planning our route and sightseeing. It was a beautiful trip thanks to all your advise. Now we're going to stay here for almost 2 weeks and enjoy the rest of our holiday!

ChantalF: Have a great time in Yellowstone - wow, very few tourists spend that much time in one place. You'll see and learn alot. The last time I was there was 40 years ago, so there's not much advice I can give.

Hopefully you will get to the Grand Tetons ... The mountains there are quite spectacular.

How exciting to have 2 weeks in Yellowstone!!!

Thanks so much for checking in and giving us a report on your trip progress.

suze, in Seattle

We were stationed in Idaho Falls for a while, so went to Yellowstone a few times. Always in the winter though, which was beautiful, but of course very different from summer! Also went to Craters of the Moon and was amazed at that! Glad your trip is going well and thanks for sharing