This access road is for hi-clearance 4WD vehicles. Not well-maintained. Switchbacks with blind rises. We made it in Darci’s 2WD S-10 but our Highlander (FWD 4cyl with hwy tires) couldn’t get up. Had to park it 2.5mi from the trailhead.
There’s another route that joins it at Sanger Lake and is 2WD passable. You have to drive further down US-199 from Cave Jct. Use this route in the future.