Closed means no fishing. If it's catch and release only, it will say so.
Honestly officer, I am a trout advocate and I feel the only way to fish these fish is with 2x tippet on this here 8wt spey rod, because we want to get them to hand as fast as possible and not risk losing any flies in the mouth of the fish. As far as the egg fly? Can't tell ya it is a family secert.i'm not an expert on washington regs but i believe you can still fish the river if it is closed to protect a certain fish. if the river is closed to all game fish then no fishing is allowed at all. if you are fishing a river that is closed for steelhead fishing but open for trout then your ok to catch trout, if you happen to hook a steelhead then it must be released imediately. if you are using say a dry fly to catch the trout it would be obvious that you are targeting trout and trout only but if your using an egg sucking leech then you might have a tough time proving to a CO that you were only fishing for trout.
like i said, im not an expert on the regs in washington so if im wrong someone please correct me.