How is the road between these two cities? It is a gray road on my map and there is no highway number designated. I would be driving a 40' motorhome and towing a car.
You should contact the local Public Works office in Newport WA to get specific information on this roadway, believe it's called the Flowery Trail. It has only been paved for the full length in the last 15-20 years, and the east side should be fairly high standard; west side might be a little narrower though. It's been many years since I was on that road going from Usk over to Chewelah, so my info is a little dated.