County Highpointers Association - Provides information for and encourages individuals to visit the highest points in every United States county. Contents include maps and charts, trip planning literature and links, elevation rules, calculators, and high point listings.
County Hunter Dot Com - A resource for amateur (ham) radio operators trying to make contact with individuals in every U.S. county. Site describes events, awards, and featured county hunters, and provides calendar, directory, photographs, discussion forums, and guides.
Extra Miler Club - Organization of road trippers who share the goal of visiting every county in the United States. Membership information and directory provided, as well as meeting announcement, travel links, and county FAQ.
National Association of Counties - Offers state by state lookup of county by city name as well as clickable state maps showing names of counties with links to geographic and demographic information for each county. Search county codes and ordinances by state, subject, or keyword.
Why Do You Think They Call Them Counties? - Site which allows users to track the U.S. counties they have visited. Includes maps, trivia, and quizzes about counties.