I believe from experience, before you take any trip to the Northwest, you check out and download or buy the " mountaindirectorys.com". They are developed for truckers and RV. Make all of your plans by Interstate. You will probably go up and catch I-80 or I-90 to go West and get to Couer d'Alene on I-90. We have done this planning as our Alaska Trip meets there. You have the Appalachians to cross but most Interstates will work okay. The West is another story. Happy Traveling