Nah, you can pee in the woods, Vinny, you just have to have a Forest Service permit signed in triplicate, and then it's only good on alternate Thursdays in months ending in "Y" :-). Sorry to say I think you're right, airguns are pretty much invisible to WDFW. Of course, that still leaves starlings, pigeons, and English sparrows, and I'm pretty sure there are some larger animals that are ignored in the regs. Maybe we need to see just how much interest in airgun hunting there is in WA, and bug the WDFW about it. I live in a great place for hunting with an airgun, lots of squirrels, marmots (g'hogs), game birds like grouse, quail, and even wild turkeys. All very reasonable game to take with an air rifle. Perhaps some sort of petition drive? Later.
Dave
