There is a paved road to Shelter Cove. The section of road from Redway to Shelter Cove is also paved - narrow winding two lane.
The route from the south along the coast to the turnoff to Shelter Cove is different and is referred to by locals as Usal Road.
Usal Rd. is dirt, one lane in many sections, rutted after the rains and muddy during the rainy season. There are tight stretches and narrow hairpins. Sometimes easily passable in 2WD, sometimes not so much. A tall roof Sprinter may have clearance issues in spots, so might a 170" WB version on the tight turns and switchbacks.
The dirt roads heading north and northeast from Shelter Cove to Mattole and elsewhere are wider and easier than Usal Road.