Our area is very scenic, too, but some of it is not practical RV country. Good area for parking the RV and using a toad, though. The following suggestions assume a toad.
Use Deception Pass SP, off SR-20 at the north tip of Whidbey Island as a base for two or three nights. Come into Anacortes the first day and wander around for a few hours. Stop off at the city's tourist office on Commercial Avenue and get maps, a ferry schedule, etc. Go up to the Cap Sante outlook for the view of Mount Baker and the north Cascades (including the oil refineries!). Head south of town on I-Avenue to Mount Erie and drive to the top. there are lookouts to the east, over the Skagit Valley and to the south over the northern part of Whidbey Island and the smaller islands around. Headed back down, there's a third lookout, looking WNW with views of the western end of Anacortes (where we live) and the San Juans. Anacortes has a big park (Washington Park) west of the ferry terminal, with several miles of waterfront and a 2.3 mile road (single lane) around the park, with stop-off areas at several viewpoints.
Then take a day to go island hopping. Take the State ferry from the Anacortes terminal and visit the three islands it stops at (Orcas, Shaw and San Juan). Shaw is small and sparsely populated and has just one general store at the terminal, but it's an interesting place and an hour or so will do it all.
Orcas is bigger and has interesting places to go. Eastsound is the "major" town, and further east is Rosario Resort, which is centered around the Moran mansion built by an early Seattle ship-builder. It's on the National Historic list and you can get a tour through it. If you go there on a Saturday, there'll probably be an organ recital in the afternoon. Also on Orcas is the highest point in the islands, Mount Constitution. It's in Moran SP and another "mount" you can drive to the top of. Form the observation tower, Vancouver BC is visible, and with a decent set of binoculars, you can see the traffic on Lion's Gate bridge.
The third island, San Juan Island is the biggest and Friday Harbor, where the ferry docks, is the biggest town. On the north shore of the island is Roche Harbor, a Mecca for boaters. John Wayne used to keep a yacht there. The old Hotel de Haro at the marina displays a guest book with a President Roosevelt's signature. The area was known for its limestone, and the old lime processing and mining equipment is still around. there's still a lot of logging activity and Roche Harbor is where the logs are dropped into the water to form rafts, which are towed to lumber mills on the mainland.
Also on San Juan is the site of the "Pig War", which almost resulted in a war between the US and the UK. The American camp is on the southwest tip of the island and English Camp is on a bay north of Roche Harbor. The west coast of the island is a good place to see grey whales, and there's a State Park at Lime Kiln Point on that coast with a big area along the beach for whale watching.
If you or family members are aviation enthusiasts, you should visit Everett, 60 miles or so south of Anacortes for the Boeing factory tour, Paul Allen's Flying Heritage museum and the Museum of Flight Restoration Center.
The Museum of Flight is a major attraction in south Seattle at the King County Airport (Boeing Field). It has walk-throughs of a British Airways Concorde, one of the Presidential 707s and the training simulator for the Space Shuttle, as well as major exhibits inside the museum. That's almost a full day, even without going into downtown!