I don't think there's much going on over that way. If you get in touch with @PowderBurnt, he may have some insight. Plus he's a great guy and loves Field Target. The only Field Target in Washington I know of are at Tacoma Rifle and Revolver, Capitol City Rifle and Pistol for winter indoor matches or Clark Rifles in Vancouver area. If you are up for the drive, Airgun Oregon is TOP NOTCH!!!
Like @Pea-shooter O.G. said, Tacoma and Clark range. They aren't AAFTA matches, but I hear they are fun. I haven't been there yet because they shoot on Saturday, which I work on.
For official matches, Ashland, Oregon is the closest. I drive there at least 3 times per year, which takes about 7.5 hours. They host an Extreme Field Target match in May, and 2 AAFTA matches in July and September.
Thanks for the response. Doesn’t seem to be much of an airgun community in Washington. Game and fish appears to have zero interest in allowing airguns as a legal method of hunting. Guess it’s a good thing I also like to fish and fling arrows.