395 is a bit slower than 97 with a few more passes, but it's a pretty central Oregon drive. This is a US highway and it sees a fair amount of truck traffic.
We've been across this area many times on many of our runs.
The windiest section is between John Day and Pendleton; it's all very good 2 lane road but give yourself time for the turns and grades - there's plenty of them. We like to describe central/eastern Oregon as "you go uphill, you go downhill. You go uphill, you go downhill... rare is the level grade." The stretch between Burns and John Day is also hilly and curvy but less so than the route on north.
Fuel is available in Lakeview, Burns, John Day, Dale, Pilot Rock, Pendleton, so you'll have plenty of opportunities to fuel up. Ukiah has a station but the operator may or may not be around the pumps, his home is just north across the street from the gas pump. It's always better to keep the upper half full than the lower half - if you have any doubts about making it to the next town, top it up. I rarely let our tank go below the half mark on our travels.
Campgrounds: We've never stayed at campgrounds/RV parks along this route, but have seen a number of RV parks in the towns mentioned above, as well and forest service campgrounds along the way.
Oregon State Parks has a good map for locating state campgrounds and parks; there are probably a few county campgrounds as well.
Hope that helps!
