I've been to Henry Coe when the normal parking by headquarters got completely filled up. Then they try to utilize the overflow parking lot which is (?) maybe a half-mile northwest. So, drivers had to backtrack to the overflow lot. But (initially) there was no parking pass capability there, so walkers had to return to headquarters, pay for parking, receive a pass, then walk it back to the overflow low, apply it to the car, and then walk back (again) toward headquarters or wherever. Obviously, they heard some complaints about that. For the next visit, there was an iron ranger at the overflow lot, but drivers still didn't know whether to stop there or to continue to headquarters to seek parking. The road is kind of narrow along there, and you don't want to be zooming back and forth in a hurry.