What is my ZIP code and/or mailing city?

The US Postal Service determines the ZIP code and postal community/mailing city associated with your address. Speak with your local Post Office regarding any new construction or try to look up existing addresses using the USPS ZIP Code Lookup website. The Gallatin County GIS Division cannot provide assistance with postal community and zip code related issues affecting delivery services. However, the GIS Division can assist if the issue is with the physical address (e.g. 123 N Counting Rd).