You can weigh it at the weigh station on I-5 southbound at about mile marker 187. Not very far from Woodinville, it's between Lynnwood and Everett. I've done it numerous times with various vehicles. I don't pull in if the weigh station is open, but I doubt if they would be very offended if you pulled in when it was staffed. You might have to read off the display in the scale house if the display ahead of you doesn't read it out. They generally have the inside display facing out so you can read it. Down south, I think there is a scale near Enchanted Village.