At a gas station on my way home from work there was a pay phone by the gas pumps. One day a few years ago I walk over to it and saw that there was no phone installed. It was just the pay phone box as seen in this example:
Ran across this site.
Maybe you could check out a local city (plug in your state) and see how current it is?
Link for California is below:
https://www.payphone-project.com/numbers/usa/CA/