Keystone South Dakota ZIP Codes
Keystone holds a single ZIP code.
Every ZIP code in Keystone
| ZIP code | County |
|---|---|
| 57751 | Pennington 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We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Keystone codes above are listed without a column we would have to invent.
Scope every ZIP code recorded for Keystone. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated . ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.
How these codes cluster
Every Keystone ZIP code begins 577. Those first three digits identify the sectional center facility that processes mail for this part of South Dakota. Statewide that range covers 58 ZIP codes, so Keystone accounts for 2% of it.
Every South Dakota ZIP prefix and the region it covers →
Area codes covering Keystone
ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The code below serves the same ground Keystone occupies.
Keystone South Dakota area codes in full →
Where Keystone's ZIP codes sit
- Reference points and footprint
- Not an official NANPA boundary
- Not a USPS delivery area
Cities near Keystone
| City | Distance | ZIP codes |
|---|---|---|
| Hill City South Dakota ZIP codes | 7.5 mi | 1 ZIP code |
| Custer South Dakota ZIP codes | 12 mi | 1 ZIP code |
| Hermosa South Dakota ZIP codes | 12 mi | 1 ZIP code |
| Rapid City South Dakota ZIP codes | 16 mi | 4 ZIP codes |
| Fairburn South Dakota ZIP codes | 18 mi | 1 ZIP code |
| Pringle South Dakota ZIP codes | 22 mi | 1 ZIP code |
| Piedmont South Dakota ZIP codes | 22 mi | 1 ZIP code |
| Box Elder South Dakota ZIP codes | 23 mi | 1 ZIP code |
Straight-line distance between place reference points, not driving distance.