We had a talk with a CNF employee last weekend about this very subject. She was putting warning tickets on peoples windows who didn't have a adventure pass. We were in a trailhead parking lot. She said they are no longer needed in the CNF UNLESS you are parked at a trailhead or in a parking lot with bathrooms, tables, maps, etc. They are marked with a triangular sign that says US FEE AREA. I asked if I park 5" outside of the parking lot would I need a pass and she said no.