For trout, most of these lowland lakes tend to get too warm or get fished out by summer. In the spring, especially the few weeks after a plant can be easy fishing for stocker rainbows. By far the easiest method is trolling woolly buggers and carey specials (I like the beadhead versions), you should be able to hook up with an insane amount of dumb eager stockers. If you dont want to patiently wait til next spring then head up I90 to Rattlesnake Lake near North Bend and try your luck there.
Hope that helps, good luck
Hope that helps, good luck