We had an interesting experience using a Forest Service Campground at Theodore Roosevelt Lake near Phoenix, AZ.
The picture shows the old iron ranger and sign at the Cholla campground where we stayed.

This picture shows the places we could purchase the needed Tonto Pass so we could camp here.
Using the Iron Ranger WAS NOT an option.

With my Old Geezer pass the Tonto Pass for one night only cost $3 but the 14 mile round trip to buy it was a little much. That cost over $3 in diesel fuel.
I complained to the district ranger the next morning but he said opening the money envelopes was an unpleasant task for his people.
We were the only campers in the entire campground as after hour campers just had to leave.
No campers must mean pleasant work for the Ranger and his people.