I live just South of you in Oregon. There are times when they require chains by law. You run them on the outer back rear. Can't say I've ever seen all four chained up but maybe they do. That being said, avoid putting them on unless you can't stay overnight or two. A lot of guys say once you run chains on the RV, the rig is never the same. The intense vibrations loosen up the cabinetry and everything else in the rig. For Oregon, go on the computer to Tripcheck. They have cams all over the passes which also give you the temperature so you know whats going on.