It's just down the road, right?
I kept crawling along at about 10 mph, telling myself, "It's probably just over the next hill or around the next bend. Don't turn back just short of the goal. After all, there are still fresh tire tracks, so others have been this far. " After about an hour I threw in the towel and turned around, for another hour's worth of crawling along a crappy road.
There were other cars by the time I got back to the trailhead. "Oh." I parked, grabbed the camera and strolled into the woods, past another small, weathered sign for Charlton Lake, and another sign for the Pacific Crest Trail. A few hundred yards later, there was the lake.