well the nice part is it's just a discovery pass if your bike is street legal to access the Washington State Parks and forest areas if your bike is already street legal and you have your endorsement. Even when I didn't have an endorsement, ORV tags and a discovery pass, nobody really made much of a fuss.I live just across the river in Oregon. Actually I can see across from the house. The daughter and SIL live in Wa. and he has a dual sport and wants me to ride with him. I guess I will have to obtain all of the Washington required passes.
if you do buy a discovery pass or your SIL buys one, you can put more than one license plate number on it.
I usually share mine with a friend. So it could be cheaper for you if you wanted to share it with your family in Washington. Just my two cents