There are some really nice campgrounds in that area of Washington
state.  Last September my wife and I stayed at Steamboat Rock, Lake
Chelan, and Pearrgin Lake.  All were quite nice and I believe they
all had showers.  Perarrgin Lake had a nice hiking trail "up the
mountain" where you could look down on the lake and campground.

http://www.camis.com/WA/camping/maps.asp?map=3

Also if you are into dams, check out the Grand Coulee dam while in
that area....they say just one of their 6 generators can power the
entire city of Seattle, a very impressive feat of engineering....to
bad it messes with the fish....

Winthrop is a neat little "wild west town" worth checking out, in
fact highway 20 from Mt. Vernon east is very scenic (hopefully it is
open at this time of year).  Much nicer than rte 2 in our opinion.
There are a couple of really secluded US Forest service campgrounds
near Twisp that we also liked.

And on highway 97 between Chelan and Oroville on the west side of the
road there is a fruit stand/cafe with free wi-fi access if you need
to catch up on your emails...

And if you travel at this time of year you won't need reservations,
just make sure the campgrounds are open and have fun!

-Paul

>In a few weeks we're planning a short trip to Olympia, Wa via Port Angeles
>on 101, then back up to Osoyoos, BC via either Hwy 20 or 2 to Oroville.
>Will need to spend one, possibly 2 nights enroute, so any suggestions for
>good places to stay would be appreciated. Will be travelling in our '82
>Westy with 2 kids, 2 cats, and a small cache of parts picked up along the
>way... ;-)