In general my experience in 2017 was that when traveling off the freeways through mountainous areas, increase your time of travel estimates. Averaging 40-45 mph on US highways and state highways is good. Averaging 35 is more common. some freeways - 40 mph average was all I could get, especially I-5 in the cities.
My rig is similar to yours. My Ram smaller gas Hemi mega cab is 22 ft long. with the 36 ft TT and a rack for the sewer tote on the back, I'm 62 ft total long and weigh a bit over 18,000 lbs. Never found any of the grades we took to be a problem, either up or down. But I planned my crossings of the major mountain ranges carefully.
From near May 1 when we left Eureka CA up into Oregon via US-199 to late August heading east on I-90 across Washington, we stayed close to the coast. Did the Olympic Peninsula Loop, including a stay at Sol Duc in the NP.
Made three trips through Portland, including a week stay right beside the river, three trips through Tacoma/Seattle nightmare.
Crossed the costal range on US-199, US-20, OR-22/130, OR-6 and US-12.
Crossed the Cascades on OR-140, OR-26, US-12, I-90, US-2 and WA-20.
In general, I'd rather follow a slow curvey relatively flat river valley than climb through higher passes. Ain't going to get anywhere fast once you leave the freeways.
In MT crossed the Continental Divide on I-90 outside Butte. Steep climb out of Butte. Got down to 45 going up the grade, but was passing 18 wheelers at the time.
My biggest issue was the metropolitan areas of Washington and Oregon.
Traveling I-5 through Portland or Tacoma/Seattle will make you long for the calm easy travel through St Louis, Atlanta or Dallas.
The freeways are simply inadequate for the volume of traffic. And it will never get better. The geography will not allow alternative routes to be built around Portland or Seattle. Kind of like finding a place to cross the Mississippi River.
US-2, one of only four possible routes across the Cascades to the coast may take six to eight hours on a weekend headed west from the Columbia River to the Sound.
The Columbia River from above Portland to the ocean has very few bridges. Congestion is heavy at times, especially the two bridges the cross in the Portland area.
US-101 up the coast is a must drive. There was construction in downtown Tillamook when we were there. Had to fold in my truck mirrors because the road was too narrow to get through without touching either the vehicle in the other lane or the signs beside the street.
Headed east just before Labor Day, we took US-95 -> ID/MT-200 -> MT-56 -> US-2 - > MT-37 -> US-93 from Couer d'Alene to Glacier NP. Simply because we wanted to see the mountains. And we planned to come out of Glacier headed to Yellowstone via Missoula.
It is a wonderful area to visit, especially for a boy raised in the flat piney woods of SW Arkansas, NW Louisiana and NE Texas. And a girl from St Louis.
We love our Ouachita/Ozarks, but the west coast mountains are something to see. Try to take your time and enjoy the little places in addition to the big bucket list spots. An unknown, unplanned almost two hour stop at Kootenai Falls on US-2 west of Libby, Mt was a very, very nice gem.
Full-Time 2014 - ????
“Not all who wander are lost.”
"You were supposed to turn back at the last street."
2012 Ram 2500 Mega Cab
2014 Flagstaff 832IKBS TT
