Residential delivery area · South Dakota
ZIP Code 57751: Keystone, SD
ZIP code 57751 uses the postal name Keystone, South Dakota and lies mostly in Pennington County (67% of its land) with the rest in Custer County (Census 2020 ZIP-county file). About 890 people live there (Census Bureau, ACS 2020-2024). Median household income is $97,969 (Census Bureau, ACS 2020-2024). By Census place, 7% of its land lies in Keystone; 93% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2020
- ZBP2023
- IRS2022
- Town
- Keystone · its only residential ZIP
- County
- Pennington County (67%); Custer County (33%)
- Census places
- Keystone
- Metro area
- Rapid City, SD
- House district
- SD at large 119th Congress
- State
- South Dakota
- Time zone
- Mountain
- Land area
- 44.2 sq mi · 20 people per sq mi
Where is ZIP code 57751?
57751 centers on 43.869°, -103.427° and covers 44.2 square miles of land plus 0.0 of water. It borders 4 ZIP codes: 57702, 57730, 57744, 57745.
The map draws ZIP code areas only. For the streets inside 57751, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 57751 compare with the rest of Pennington County?
| Measure | 57751 | In Pennington County | In SD |
|---|---|---|---|
| People (ACS 2020-2024) | 893 | 14th of 20 | 156th of 375 |
| Median household income | $98k | not ranked | not ranked |
| Median home value | $474k | not ranked | not ranked |
57751's income and home value are not ranked: it has fewer than 1,000 residents (893). Rankings use ZIP codes of 1,000 or more people living in households, with margins at most 25% of the figure.
It is denser than 26% of U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 57751?
The 2020 Census counted 717 people in 57751; the ACS, which samples households over 2020-2024, estimates 893. Its boundary changed between the 2010 and 2020 censuses, so the two counts are not compared.
- People, ACS 2020-2024
- 893±228 (90% margin)
- 2020 Census count
- 717
- Households
- 327
- Median age
- 54.2
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 57751?
Of the 893 people the ACS estimates in 57751, 19.5% are under 18 and 23.4% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (84.7%).
- Under 1819.5%
- 18 to 6457.1%
- 65 and older23.4%
- White, not Hispanic84.7%
- Hispanic or Latino9.0%
- Other or two or more4.7%
- Asian, not Hispanic1.6%
- Black, not Hispanic0.1%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 57751 earn?
Median household income is $97,969 (ACS 2020-2024).
- Median household income
- $97,969±$34,026
- Income per person
- $43,414
- Below the poverty line
- 4.6%
- Unemployed (of the labor force)
- 2.9%
- Adults 25+ with a bachelor's degree
- 43.0%
- Adjusted gross income per tax return, 2022
- $70,941560 returns; wages 51% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 57751?
- Median home value (owners' estimate)
- $473,500
- Median gross rent
- $600
- Homes owned by their occupants
- 85.6%
- Housing units
- 477
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 57751?
72 business establishments had a location in this ZIP code in 2023, 1 more than in 2018; the most are in accommodation and food services (ZIP Code Business Patterns).
- Accommodation and food services31
- Retail trade16
- Arts, entertainment, and recreation8
- Transportation and warehousing4
- Health care and social assistance4
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 57751?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 57702 | Rapid City | 35,595 | $92k | 11.3 mi |
| 57730 | Custer | 5,596 | $84k | 14.8 mi |
| 57744 | Hermosa | 2,421 | $106k | 20.3 mi |
| 57745 | Hill City | 1,894 | $88k | 20.4 mi |
| 57738 | Fairburn | 356 | $52k | 18.5 mi (near) |
| 57773 | Pringle | 206 | – | 20.7 mi (near) |
| 57701 | Rapid City | 45,795 | $57k | 20.8 mi (near) |
| 57718 | Black Hawk | 7,937 | $84k | 21.0 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.