Not kidding, but maybe not completely accurate. I checked my memory against other sources as it's been 25-30 years, at least one county has an ordinance prohibiting it. It was an April fools day thing, but has been amended a couple of times. We had a professor at WSU that was into Bigfoot bigtime. He was always going to shoot one for proof, I recall the state doing something, It may be the Undiscovered Species Protection Act, but I can't find enough to back that up right now
You are apparently correct, at least in Skamania County. In 1969 the county adopted ordinance 69-01 making killing a bigfoot punishable with a $10,000 fine and up to 5 years in jail!
http://www.skamaniacounty.org/ordinance/Bigfoot Ordinance 69-01.pdf
However, the felony charge and penalty was repealed by the commissioners in 1984 and Skamania County was declared a "Sasquatch refuge". Not sure what happens if you killed one in a "refuge".
http://www.skamaniacounty.org/ordinance/Bigfoot Ordinance 1984-2.pdf
There it is folks, guvmint at work. Stranger than fiction...you can't make this stuff up.
Thanks HarperC...this made my day.