Lake Washington does have Rainbow Trout , As far as Walleye I'm not sure as I never have caught any and the reports I've seen are from people that confuse the walleye with squaw fish or sometimes large perch. Also heard reports that some have caught Sauger and confused them as Walleye. Either way if there is any walleye or Sauger they had to have been plated illegally as they are not native to the lake. The lake does have a Salmon {COHO} migration, in the early too late Fall and can be pretty good fishing jigging and trolling for them. These fish come thru from the ocean to Puget sound thru our Ballard locks and into Lake Union .
Please look me up when you do get here as there other options and hopefully help each other to improve on our quest to catch Crappie. One thing that I must point out is there is a high level of PCB in the lake that suggest limiting the amount of fish you eat.