[Dusters]

If you have never been through Portland I-5, there are multiple levels of overpasses and lane changes. I find it a very stressful drive and prefer the I-205 Bypass as easier to navigate with a trailer, even though it's a few miles longer and full of commercial trucks.
Another item on the Sam's club map or Google map is down I-5 just past mile marker #162 is the Highway 38 to Reedsport. This is a commercial highway for trucks, which has a two lane highway through a tunnel at Elk Creek Tunnel Forest. One map posted a 12'4" warning for the outer curvature and overall height should be 14 feet.