Seattle area camp grounds

You may want to consider Gig Harbor RV park. Really cool little fishing town to stay in. You will have to take a toll bridge ($4) to get to mainland).. It is a different adventure.

If it's the Middle Fork CG that I'm aware of, it's an awesome little CG but it is at the end of 10 miles of a severely BOMBED out dirt road.

There are a couple of decent RV parks on east of Seattle in Fall City area that are in a nice rural setting and close to I-90. I-90 is the least traffic clogged road in the Seattle area. I-5 is bad to horrible most of the time.

Enjoy the Museum! BTW, there are two other small aviation museums up at Paine Field in Everett. Got to sit in a P-51 a couple years ago!!

I live real close to that. Little bit off topic as you said you wanted a campground close, but if you need to park when hooked up Randy's Restaurant in the back lot at 47.513016,-122.293293 has room and not uncommon to see rigs parked there. Restaurant is real "greasy spoon" but also has a lot of old Boeing stuff in it. Museum is short walk away. Just in case you wanted the option of camping somewhere else or out a bit more but also want to see museum as your going by. You could also park closer but more of a hassle IMO

There aren't many parks near downtown Seattle, and very few in King County. You could stay up near the pass at Easton State Park or one of the private campgrounds there. That's about an hour from Seattle, and is cool at night.

You might also want to go up to the restaurant in the Space Needle, take a roundtrip ride on the ferry to Bremerton (where you can see the Navy ships), and/or visit the public market on Pike and First street in downtown Seattle.

Lake Pleasant for us too. Going back this fall for another stay. Nice place, quiet, handy access to freeway for touristing.

Lake Pleasant RV Park in Bothell is one of the nicest parks we have seen. Clean,quiet,very well maintained, many of the sites back onto the lake edge. Shopping center across the road. Lots of ducks to keep the kids and dogs entertained. It is a short drive off 405 which allows easy access to the city.