ZIP Code 99110

99110 is one of Washington's ZIP codes, delivering to addresses in Clayton, Stevens County.

City: Clayton
County: Stevens County
State: Washington
Prefix: 991xx

Where this code sits

99110 is part of the 991xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Clayton.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 99110 delivers to without sharing its boundary.

509 Area code 509

ZIP codes nearest 99110

The ZIP codes whose reference points sit closest to 99110.
ZIP code	Distance	Delivers to
ZIP code 99006	5.2 mi	Deer Park, WA
ZIP code 99148	6.0 mi	Loon Lake, WA
ZIP code 99034	12 mi	Tumtum, WA
ZIP code 99009	12 mi	Elk, WA
ZIP code 99173	13 mi	Springdale, WA
ZIP code 99181	13 mi	Valley, WA
ZIP code 99013	13 mi	Ford, WA
ZIP code 99003	14 mi	Chattaroy, WA

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 99110, plotted from its record coordinates.

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

Scope ZIP code 99110. 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.