Three miles west of Anacortes [1], the city-run Washington Park [2] (360/293-1918, $12 tents, $15 RVs) has crowded campsites in the woods, with showers and boat launches. No reservations are accepted.
Two popular state parks with campsites are within 20 miles of Anacortes: Deception Pass State Park [3] near Oak Harbor [4] and Bay View State Park [5] near Mount Vernon [6].
Park RVs at Fidalgo Bay Resort (1107 Fidalgo Bay Rd., 360/293-5353 or 800/727-5478, www.fidalgobay.com [7]), Lighthouse RV Park (1900 Skyline Way, 360/293-3344), or Pioneer Trails Campground (527 Miller Rd., 360/293-5355 or 888/777-5355, www.pioneertrails.com [8]). Pioneer Trails even has covered wagons for family camping.
Links:
[1] http://www.moon.com/destinations/washington/san-juan-islands/anacortes
[2] http://www.moon.com/destinations/washington/san-juan-islands/anacortes/sights/washington-park
[3] http://www.moon.com/destinations/washington/north-puget-sound/whidbey-island/deception-pass-state-park
[4] http://www.moon.com/destinations/washington/north-puget-sound/whidbey-island/oak-harbor
[5] http://www.moon.com/destinations/washington/north-puget-sound/skagit-valley-and-mount-vernon/sports-and-recreation/camping
[6] http://www.moon.com/destinations/washington/north-puget-sound/skagit-valley-and-mount-vernon
[7] http://www.fidalgobay.com
[8] http://www.pioneertrails.com