Seneca Oregon ZIP Codes

Seneca holds a single ZIP code.

Every ZIP code in Seneca

The complete list of Seneca, Oregon ZIP codes with the county each falls in.
ZIP code	County
97873	Grant County

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Seneca codes above are listed without a column we would have to invent.

Scope every ZIP code recorded for Seneca. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.

How these codes cluster

Every Seneca ZIP code begins 978. Those first three digits identify the sectional center facility that processes mail for this part of Oregon. Statewide that range covers 54 ZIP codes, so Seneca accounts for 2% of it.

Every Oregon ZIP prefix and the region it covers →

Area codes covering Seneca

ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The codes below serve the same ground Seneca occupies.

Seneca Oregon area codes in full →

Where Seneca's ZIP codes sit

Each point is one Seneca ZIP code, plotted from its record coordinates.

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

Cities near Seneca

The closest places to Seneca with their own ZIP code list, nearest first.
City	Distance	ZIP codes
Canyon City Oregon ZIP codes	18 mi	1 ZIP code
John Day Oregon ZIP codes	20 mi	1 ZIP code
Mount Vernon Oregon ZIP codes	21 mi	1 ZIP code
Prairie City Oregon ZIP codes	26 mi	1 ZIP code
Dayville Oregon ZIP codes	36 mi	1 ZIP code
Burns Oregon ZIP codes	38 mi	1 ZIP code
Hines Oregon ZIP codes	40 mi	1 ZIP code
Long Creek Oregon ZIP codes	41 mi	1 ZIP code

Straight-line distance between place reference points, not driving distance.