ZIP Code 59631

59631 is one of Montana's ZIP codes, delivering to addresses in Basin, Jefferson County.

City: Basin
County: Jefferson County
State: Montana
Prefix: 596xx

Where this code sits

59631 is part of the 596xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Basin.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 59631 delivers to without sharing its boundary.

406 Area code 406

ZIP codes nearest 59631

The ZIP codes whose reference points sit closest to 59631.
ZIP code	Distance	Delivers to
ZIP code 59632	7.9 mi	Boulder, MT
ZIP code 59638	8.7 mi	Jefferson City, MT
ZIP code 59634	14 mi	Clancy, MT
ZIP code 59728	15 mi	Elliston, MT
ZIP code 59623	20 mi	Helena, MT
ZIP code 59620	20 mi	Helena, MT
ZIP code 59624	20 mi	Helena, MT
ZIP code 59626	20 mi	Helena, MT

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 59631, plotted from its record coordinates.

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

Scope ZIP code 59631. 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.