It's not very well enforsed Just my thought's lots of place to park, so I wouldn't worry about them, seen those sign's last trip north in 17 but just ignore them, if you are too tired nobody will move you along, and as far as enforement none to be seen on the hwy.
98 Mountain Aire 34' 210 Cummins Puller and 2001 dodge dully with all the toy's, 400 + hp pullin a 2001 32.5' Okanogan 5th wheel, new to us after 5 yrs with the 28' Travel Aire. Lots of fun.