Not being familiar with any Washington fishery other than the Sound I just googled it and the Lower Yak and Columbia came up. Obviously the John Day and S. Umpqua in Oregon but those are predominantly smaller fish which is often the case for rivers. I prefer lakes or large, slow moving rivers as the fish are generally larger. I use a 5-6 wt. rod, rarely fish the surface, and use mostly Zonkers, large buggers, and crayfish patterns. Look for rocks over wood as their main forage is crayfish and baitfish. Fish tight to rock walls and bump your fly over rocky bottoms. Use a Type I-Type II line for most areas, and do the countdowns and fish the water column down. Smallies can be anywhere in the column. They act more like trout than LMB and do like a little current. I routinely fish them down to 20' in mid summer as they prefer colder water than the LMB, and at that depth use a Type 4 or T-200-350. Sometimes a fast strip is the key, but of course when fishing craw patterns you want short strips with pauses. When fishing baitfish patterns I've found fast stripping in the current seam (if available) is often the best when the WT >60.