Definitely keep the app in mind. It's super useful. There's a ton of lakes in WA in the app, plus the coastal areas and Puget Sound. Even most of the itty bitty 20 acre lakes on the west side are there.

It works on tablets too. Plus it has a GPS function so it will show you where you are on the lake. Great for ice fishing since you can find the approximate depth without drilling holes. I take my phone out with me all the time.