Union County Post Offices

21 Amistad Rd
Amistad, New Mexico 88410

1 Walnut St
Clayton, New Mexico 88415

720 Broadway Ave
Des Moines, New Mexico 88418

53 Grand Ave
Folsom, New Mexico 88419

16 5th Ave
Grenville, New Mexico 88424

508 Callis Rd
Sedan, New Mexico 88436

Union County

There are 6 US Post Offices in Union County serving a total of 4,534 residents equating to 756 residents per post office. It's estimated that approximately 7,237 packages are handled across the 6 county post offices annually. Union County is the northeasternmost county in the U.S. state of New Mexico. As of the 2010 census, the population was 4,549, making it the fourth-least populous county in New Mexico. Its county seat is Clayton. The county was formed in 1894. Union County borders Colorado to the north, and Oklahoma and Texas to the east."