Crappie fishing here is seasonal for the most part. The main reason you don't see a lot people talk about it form Washington is there are bigger fish to fry. Salmon, steelhead, sturgeon, trout, salt water fish and other fish really dominate the fishing here.
There are hundreds of lakes that have crappie in them, I would say 90% of all lakes in the state have crappie, blue gill and perch in them. The main trouble is the water stays cold for so long that the spawn doesn't even start until May, sometimes June depending on the lake and where it is. East side of the state it starts earlier, sometime sin late March early April. I have seen bass and crappie on beds as late as June 14th. So they start a little late here.
Just not as many people fishing the although I have seen some monsters caught and really love to fish panfish.
I love taking my kids fishing, now if I could just manage to fish at the same time.