should be big and flat.
Likewise, your rivers should be (1) fishable and (2) infested with Steelhead for a reasonable chance of success.
The problem with July on a high snowpack year is (1). That leaves you the rocky Columbia tribs (especially ones that have dams) and a few Puget Sound rivers like the Sky and NF Stilly if the weather is cool.
Flows usually stabilize by early/mid August. The levels drop and floating line/fly becomes the preferred way to fish. August fishing is usually good in all areas - OP rivers like the Sol Duc, Hoh and Elwah. The Puget Sound and Columbia tribs are all worth a shot as well.
That being said, summer fishing is usually quite a bit more relaxing and productive that winter/spring fishing.