Ok my friend I live in maple valley and can set you up proper.
My three boys, wife, and I have had very good success at lake wilderness over the years.
The lake is stocked to the top with rainbow trout.
Here is the trick to cathing fish from the shore at wilderness.
There is a penninsula between the boat launch and the dock. You can't miss it it extends out far. Go to the very tip of the point and cast strait out. There is a deeper spot out there that the trout school in. one to five minutes between bites. Don't try to set the hook just let them play with it until your shure there on.
You will need to pick up a jar of green and yellow power eggs. Use red hooks, not to big (we are talking about small trout). light line 6# test and enough weight to get you out there far.
Here is the set up.
_____6lb_______slip sinker(maybe two)__6lb_____________snap swivel-----------leader 4 or 5 feetlong-----hook
Some last notes for you be for you go.
There will be other people fishing there. #1 fish there anyway, I have had very little success fishing from shore any were else on this lake. #2 The people fishing there are very nice, they will be happy to help put you in the right spot. usualy the same people fishing there Every weekend.
#3 always, always, have a backup lake when shore fishing. Your back up lake is lake meridian. not to far from lake wilderness and it has very good dock fishing. I don't think you will have any problem there people seem to catch fish with multiple different presentations. less action but still very good. Just use what every is working for the other people on the bock.
Ok your on your own from here. I will be looking for a very impressive fishing report from trout magnet at lake wilderness or meridian. Good luck to you and your son.
needabiggerboat