ZIP Code 99174

99174 is one of Washington's ZIP codes, delivering to addresses in Steptoe, Whitman County.

City: Steptoe
County: Whitman County
State: Washington
Prefix: 991xx

Where this code sits

99174 is part of the 991xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Steptoe.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 99174 delivers to without sharing its boundary.

509 Area code 509

ZIP codes nearest 99174

The ZIP codes whose reference points sit closest to 99174.
ZIP code	Distance	Delivers to
ZIP code 99176	8.4 mi	Thornton, WA
ZIP code 99111	8.7 mi	Colfax, WA
ZIP code 99130	9.6 mi	Garfield, WA
ZIP code 99104	9.8 mi	Belmont, WA
ZIP code 99158	10 mi	Oakesdale, WA
ZIP code 99171	11 mi	Saint John, WA
ZIP code 99128	14 mi	Farmington, WA
ZIP code 99161	15 mi	Palouse, 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 99174, plotted from its record coordinates.

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

Scope ZIP code 99174. 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.