I received extra credit at school last year for helping with the salmon watchers on lake washington. One of the most interesting things i found was that some salmon will spawn on the beach below I-90. Theirs a park there and a kayak rental shop in the summer. in october to december I checked this beach every other day. in october while it was raining the salmon spawned on the beach. They think this is becouse they have a hard time going up coal creek. the mouth of coal creek is to shallow at that time of year. http://dnr.metrokc.gov/wlr/waterres/salmon/
heres the link if you are interested.