There are 2 Post Offices in Union, California, serving a population of 74,354 people in an area of 20 square miles. There is 1 Post Office per 37,177 people, and 1 Post Office per 9 square miles.
In California, Union is ranked 1,050th of 1798 cities in Post Offices per capita, and 944th of 1798 cities in Post Offices per square mile.
Find addresses, phone numbers, fax numbers, hours & services for Union Post Offices.
United States Postal Service 33170 Alvarado Niles Road Union, CA Mailing Service, Postal Services
United States Postal Service 3861 Smith Street Union, CA Mailing Service, Postal Services