ZIP Code 81638

81638 is one of Colorado's ZIP codes, delivering to addresses in Hamilton, Moffat County.

City: Hamilton
County: Moffat County
State: Colorado
Prefix: 816xx

Where this code sits

81638 is part of the 816xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Hamilton.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 81638 delivers to without sharing its boundary.

ZIP codes nearest 81638

The ZIP codes whose reference points sit closest to 81638.
ZIP code	Distance	Delivers to
ZIP code 81626	13 mi	Craig, CO
ZIP code 81625	14 mi	Craig, CO
ZIP code 81639	21 mi	Hayden, CO
ZIP code 81641	26 mi	Meeker, CO
ZIP code 81633	43 mi	Dinosaur, CO
ZIP code 81640	48 mi	Maybell, CO
ZIP code 81653	48 mi	Slater, CO
ZIP code 81647	52 mi	New Castle, CO

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 81638, plotted from its record coordinates.

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

Scope ZIP code 81638. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.