The actual mountain pass section has a couple of turns in it but it's a major multi-lane highway at those points and only a few miles long. After that it turns into a scenic two lane highway that's perfectly pleasant to drive because the hills are very gentle - you'll probably have to give it a little throttle to keep up to speed in most cases. Also the road is kept in great repair. It is curvy but they aren't tight curves as the speed limit is mostly 50+ mph.
It's truly one of the most beautiful routes in Wa. State.
