Sierra County ZIP Codes

Sierra County is a county of New Mexico.

ZIP codes: 10
Cities & towns: 10
Area codes: 1
Land area: 4,181 sq mi

Every ZIP code in Sierra County

876xx–880xx

The complete list of Sierra County, NM ZIP codes with the city each one delivers to.
ZIP code	City
87654	Spaceport City
87901	Truth Or Consequences
87930	Arrey
87931	Caballo
87933	Derry
87935	Elephant Butte
87939	Monticello
87942	Williamsburg
87943	Winston
88042	Hillsboro

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Sierra County codes above are listed without a column we would have to invent.

Cities and towns in Sierra County

A further 7 places in Sierra County appear in the postal source without a page of its own; their codes are in the table above and each one links to its own page.

Area codes covering Sierra County

Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.

505 Area code 505

Where Sierra County's ZIP codes sit

Each point is the reference point of one Sierra County ZIP code, plotted from its record coordinates. The outline is the convex envelope of those points — a footprint, not a boundary.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope every ZIP code recorded in Sierra County. Source GeoNames US postal codes (2026-07 postal dump), Census 2024 county Gazetteer (2024 Gazetteer) and geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot). Updated 16 July 2026. The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.