I would add that some of us have been doing the coho salmon on the fly thing for over a decade and it's exploding lately. Besides it's about the most fun you can have with the bugrod... ON THE OCEAN! Those chrome-bright ocean feeder salmon are a total kick!
In late fall lots of people get flyrods busted by chum salmon, but they don't admit it.
There are five pacific salmon species and steelhead running throughout the year, and yes when you can greaseline a summer run steelhead on the surface there is little incentive to fish for upriver salmon in the fall.