WA is excellent about getting the regs detailed, although some of the wordings are ambiguous on certain regions, etc.
Here is more than you could ever want to get for perspective on their regs:
Look under selective fishery fly fishing only
In the PNW, drift fishermen abound but do not use fly rods and do not call it fly fishing. The majority of drift anglers use drift gear, which is predominately level wind reels on 8.5 foot trigger handled rods, or spinning rods. Most use extruded lead or slinkies to drift corkies or bait or a combination along the bottom of the river, bringing the offering to the nose of the fish.
Fly fishermen do not use weights on the line and swim the fly over the fish getting them to move to the fly and strike it. It's not as easy as drift fishing but with practice it can be deadly.
One needs to think differently about the water to fish, and the techniques to use. Where drift fishing concentrates on breaking down the resistance of generally dour fish sitting in concentrated groups, swinging a fly focuses on covering a lot of water effectively and really working the dynamics of the flow and structure to present the active fly to aggressive fish.
Granted the frigid temperatures of the midwest and east create more instances of dour holding fish, they are still moving toward the headwaters and active enough to grab a fly if presented properly.
There is a fairly steep learning curve to reach proficiency but the satisfaction of reaching that level is indescribable and not measured so much by the fish hooked but equally in the skill of the angler.
Eventually the angler reaches a new level of proficiency and has the ability to catch fish consistently with beautifully tied spey flies and in summer months surface flies on dry lines, all on the swing.
I understand how the general approach gravitates toward drift fishing with fly rods, as there is no real separation and the fly water permits it. If the fly water regs prohibited the use of weights and people started having to swing flies in the fly water, the crafty anglers of the region would quickly become proficient with these more traditional techniques. But as long as people are allowed to chuck and duck in fly water, stand on one rock all day, the advances in these techniques will remain unrealized, IMHO.
The short story - see the river differently, fish different water, and relate to the fish in ways unconventional to the drift angler and eventually it will all come together.
Think of the drift boater pulling plugs. Is he fishing a weighted little nymph close to the bottom? Nope, he is running a vibrating glorified bass plug in neon colors through the same pool and banging big steelhead. What does that tell us?
Thanks for asking.