question regarding highway 20 through Washington State

There are few towers out there as underpowered as I am when I'm out and about with my 4-cyl Kia/2,000 pound trailer combo. I've been over Hwy 20 a number of times with those- if I can do it, you can! My experience is that traveling from east-to-west is an easier tow since one starts at a higher elevation to begin with in that case.