Check out the redwoods using US 101. California Highway 1 is narrow with very sharp turns and not, in my opinion, a good or safe road for RV's of any type. Most of the redwood area is in Northern California and you can get to the upper end as mentioned above from Grants Pass Oregon - using HWY 199. There are a few miles on 199 that have sharp 15 mph corners but overall a good road.
Bob, Sandi & Marmaduke the Big Pug
SW OREGON 2004 Journey 39K, 330 Cat
If towing: a 2006 Mini Cooper or 1995 Wrangler