location_county
This Drupal module provides a county field for the Location module. To use, put the location_county folder in Drupal's modules directory (i.e. sites/all/modules) and enable the module.
Depends on Location module (https://www.drupal.org/project/location).
Original issue can be tracked at https://www.drupal.org/node/221370 . A patch for the Location module is also available there, which adds this module to the contrib folder of Location.