I have driven that route a couple of times in the EX pulling a 35' TT,but don't remember too much about the road. At 28K in weight,I would be kind of concerned about that 16K limit especially when adding the 3700 of the toad.
I'm thinking about dropping the MH in Vancouver and taking the toad to Portland to pick her up and then head up #14. Last time I picked her up at Terwilliger Plaza,they weren't too happy about a 40' MH and toad in their parking lot.It was a tad bit tight,but when you've driven a school bus for 13 years and a step van for 31 years,accident free,you learn where you can push it or not.
Bruce and Sue, the last time she and I were over your way,she had a painting of that really neat red house on the south side of Goldendale that the rancher built for his Indian wife.The house was for sale and the realtor was able to take us thru it. She found the pix at a garage sale in Bend and remembered it from her first date with my Uncle Bill. They drove down from Yakima to pick up some dahlia bulbs for my Grandmother and that must have been quite a trip in the late 30's.