For those who are attending the MOA rally in Redmond, but aren't especially time-limited, bear in mind that the Washington State rally is the following weekend, down in the vicinity of Willipa Harbor. You could easily explore the Columbia Gorge, go see what's left of Mt. St. Helens, take a ride around Mt. Rainier, do some sightseeing in the Seattle area, take in Whidbey Island, make the loop of the Olympic Peninsula, and arrive at Menlo Park in time for the WA rally.
Who knows? I may be there myself.
There are some other areas that are well worth a visit. Crater Lake is spectacular--being the caldera of an ancient volcano that blew it's top.
The Oregon coast is worth exploring. Lots of wild beaches, lighthouses, harbors, and of course more than a few motorhomes. If you relax and take in no more than 8 or 10 scenic beaches in a day, you'll have a good time. One of my favorites is Depot Bay, where there is a tiny bay on the east side of the highway, and a narrow, twisty channel heading right out into the ocean. The bridge makes a great viewing spot. I'm always holding my breath as a fishing boat comes sliding in on a breaker, pointed straight at the rocks, then the skipper somehow manages to get it turned and through the narrow passage. Whew!
If you study any tourist guides of the Oregon coast, you'll discover where to find the Sand Dunes, the aquarium, Sea Lion Caves, and the Tillamook Cheese factory. I'm not trying to be comprehensive here, just hoping you'll think about taking in a very spectacular coastline that's still not too over-run with tourists.
The Washington coast is also very wild and scenic, but the highway is often inland a few miles, so with a few exceptions you'll need to hang a turn and head out on a side road.
If you would like to bag the northwesternmost tip of the continental USA, that would be Cape Flattery, down a dirt road from the Neah Bay reservation.
Like seafood? Salmon is king here, but Dungeness crab and Willapa oysters are also available, and there's nothing like fresh seafood.