This is a problem in Kentucky. There is a legal process for closing a county road but it is rarely followed.
County governments do not want to maintain these old roads due to the cost, yet they are reluctant to close them while they are still used by adjacent landowners. They just quit listing them as county roads and claim no responsibility. But they might even still work on them if the right person requests it.
This leaves a sort of legal limbo you do not want to be involved with if you can help it.