I stumbled onto this area last summer when I took my bike from the Anacortes ferry terminal to Bellingham. On the way to Bellingham I made the mistake of taking I5 - awful!
However, on the way back from Bellingham to Anacortes, I took the back roads along the ocean - and was very pleasantly surprised. The roads themselves are mostly straight, quiet farm roads. Not exciting but there is little traffic, and the view in places are excellent. Overall a nice surprise.
Really nice views, some nice corners, road narrow in places, so use caution.