ZIP Code 17840

17840 is one of Pennsylvania's ZIP codes, delivering to addresses in Locust Gap, Northumberland County.

City: Locust Gap
County: Northumberland County
State: Pennsylvania
Prefix: 178xx

Where this code sits

17840 is part of the 178xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Locust Gap.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 17840 delivers to without sharing its boundary.

ZIP codes nearest 17840

The ZIP codes whose reference points sit closest to 17840.
ZIP code	Distance	Delivers to
ZIP code 17851	1.9 mi	Mount Carmel, PA
ZIP code 17834	2.4 mi	Kulpmont, PA
ZIP code 17832	2.6 mi	Marion Heights, PA
ZIP code 17943	3.0 mi	Lavelle, PA
ZIP code 17945	3.3 mi	Locustdale, PA
ZIP code 17888	3.6 mi	Wilburton, PA
ZIP code 17921	5.0 mi	Ashland, PA
ZIP code 17920	5.5 mi	Aristes, PA

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 17840, plotted from its record coordinates.

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

Scope ZIP code 17840. 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.