The highest summit in SoCal is 4,183 ft. Signs just past the Oregon border note the highest point on I-5 at 4,310 ft. Even if the pass is open, you may be required to carry chains for the trailer in addition to chains for the truck in Oregon and Washington.
Golden_HVAC wrote:
Going north on I5 can be easy, you can wait out any storms, and just travel a day or two later once the roads are cleared. But once in Washington, if you need to be there say on the 20th, you will need to drive on no matter what. ..
There are only major passes over the 'grapvine' just north of Los Angeles at around 6,500' elevation. It rarely snows there, but there is highway 14/58 through Mohave to Bakersfield to bypass that around 3,500' elevation.
Northern California to the Oregon border is another pass, around 5,000', that can be snowed in for a day or two, but most likely will be open. Leaving Grants Pass is a triple set of hills, only about 1,500' climb each, and then it is basically a valley all the way to Portland OR>