Yes, this is a fishing area. If you are unsure, check fish and game website. Just Google lake Washington fishing piers and it will list all of them flushable to the public.
Apparently you can. Checked the parks website.
I would check with the parks dept. I'm sure they have a list of free fishing sites
I've seen people fishing from the dock when I've been there, but I don't know about official park rules.
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