Do a google search for Whidbey beach steelhead and this is the first result.

http://www.piscatorialpursuits.com/forum/ubbthreads.php/topics/84118/Whidbey_Steelhead.html

I used to fish Ft. Casey about 20 or so years ago in November and December when the rivers were blown out. Caught a few steelhead using the same setup described in the link but never fished it consistently enough to really figure it out. I always thought trolling the shoreline like you would for sea-run cutthroat using the beach rig would work well for saltwater steelhead.