question regarding highway 20 through Washington State

IMO, SR20 is an easier run than US2 and it's our preferred route. That nay be because we live out at the west end of the spur that goes to the State Ferry terminal in Anacortes. State DOT were finishing up some road improvements on the west side when we came through last year, but we haven't been over SR-20 so far this year. It's typically our route for an early September trip. If you're headed west, through Winthrop, it's a steady climb to the top, but it's a well maintained road and wider than US2. My 32' V-10 Class A ran 35 - 40 mph all the way up without getting hot. Washington Pass is about 1000 ft higher than Stevens, but the grades are manageable and the views are worth the trip.

Something to consider, between Concrete and Burlington is to take the South Skagit Highway instead of staying on 20. Headed west on 20, take the road to the south about 3/4 mile west of Concrete, just before the grocery store on the south side (not the cross-road where the concrete storage tanks are). After the trestle over the river, turn immediately right onto the South Skagit Highway. Eventually, you end up at a junction with Highway 9. Head north on 9 into Sedro-Woolley and back onto SR-20 headed west. A minor diversion, but a very pretty drive along the south bank of the river. I used to drive transit part way down that route.

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.

without knowing what you're pulling with, not sure if anyone can answer for sure.

it's not a bad tow if your TV is adequate. the downhill into Winthrop is a little sketchy, due to sharp turns and downhill grade.
IMHO, it's the only section that requires your complete attention.

It's a beautiful drive though!

Reading from the "Mountain Directory - West" (highly recommended) "It is a good two lane road with passing lanes during the clumbs. Eastbound descent from the summit of Washington Pass - 7% grade over 7 miles - 30-40mph curves. Use caution.

Westbound descent - 4 mi of 6-7% grade. At this point the climb to the summit of Rainy Pass begins. The summit is reached after a 1 1/2 mile 5-6% climb.

Westbound from Rainy Pass - 6% grade 4 miles. Then a 3 mile flat section and another 3 mile 3-5% downhill grade followed by a 1 mile flat section and then a sign 'steep 5-6% grade next 3 miles'. There is a lot of downhill left until Newhalem is reached 26 miles from this sign."

It's a typical mountain road with all the climbs, descents, and sharp curves one should be prepared for. The grades are 5-7% with most being no longer than 3 miles. Very doable assuming you have an adequate tow vehicle for your 32 foot trailer.

The climb to WA pass going Westbound is pretty tough. Other than that, not so bad.