This is the section of the Gazos Creek Trail inside the Big Basin Redwoods State Park. The road continues a ways from the park boundary as a seasonally open access road beyond Sandy Point. As a fire road, it's quite wide. It starts with a steady climb, but it's quite shady.
After about 1.3 mile, you'll pass on your right the Middle Ridge Road
. Continue until you get to Sandy Point if you're following the Big Basin Loop