US101 east from PA follows Hood Canal south to Olympia and I5. This is a nice drive along an inland waterway, with lots of state parks. I5 from there is the fastest way to Portland.
US101 west from PA gives more access to the Nat Park, mostly via side trips to the beach (at Forks) or up river valleys. Most of it is inland (through forest), with only one part that follows a wild outer coast. Further south you can take side trips to beach communities like Oceans Shores, Westport and Long Beach. After crossing into Oregon you can take US30 east to Portland.
Some dismiss the Washington portion of US101 because it doesn't hug the coast as much a the Oregon part. Still, if I have time, I prefer the sights along, and off of, (west) US101 to the sights along I5.