The QuickFacts tool at the U.S. Census Bureau website can be used to determine the county in which a person resides. Type the city and state or zip code into the search box, and click Go to locate your county.
The county of the city or town is displayed on the ensuing screen. Clicking the hyperlinked name displays a variety of countywide data, including demographics as well as business and geographical information relative to the state as a whole. Townships that lie outside the limits of a certain zip code may be located in a county other than that of the neighboring city.