Residential delivery area · South Dakota
ZIP Code 57231: De Smet, SD
ZIP code 57231 uses the postal name De Smet, South Dakota and lies entirely in Kingsbury County (Census 2020 ZIP-county file). About 1,700 people live there (Census Bureau, ACS 2020-2024). Median household income is $78,646 (Census Bureau, ACS 2020-2024). By Census place, under 1% of its land lies in De Smet; more than 99% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2022
- ZBP2023
- IRS2022
- Town
- De Smet · its only residential ZIP
- County
- Kingsbury County
- Census places
- De Smet
- House district
- SD at large 119th Congress
- State
- South Dakota
- Time zone
- Central
- Land area
- 249.3 sq mi · 7 people per sq mi
Where is ZIP code 57231?
57231 centers on 44.376°, -97.582° and covers 249.3 square miles of land plus 12.9 of water. It borders 8 ZIP codes: 57249, 57353, 57233, 57051, 57323, 57221, 57278, 57349.
The map draws ZIP code areas only. For the streets inside 57231, 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 57231 compare with the rest of Kingsbury County?
| Measure | 57231 | In Kingsbury County | In SD |
|---|---|---|---|
| People (ACS 2020-2024) | 1,724 | 2nd of 9 | 82nd of 375 |
| Median household income | $79k | 3rd of 4 | 46th of 107 |
| Median home value | $212k | not ranked | not ranked |
57231's median home value is not ranked: its 90% margin of error (±$62,322) is more than a quarter of the figure ($212,200). Rankings use ZIP codes of 1,000 or more people living in households, with margins at most 25% of the figure.
Its median household income is higher than in 60% of U.S. residential ZIP codes, and it is denser than 13% of all 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 57231?
The 2020 Census counted 1,674 people in 57231; the ACS, which samples households over 2020-2024, estimates 1,724. Between the 2010 and 2020 censuses its population fell 1.2% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 1,724
- 2020 Census count
- 1,674−1.2% since 2010 (1,695)
- Households
- 721
- Median age
- 44.2
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 57231?
Of the 1,724 people the ACS estimates in 57231, 25.3% are under 18 and 26.3% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (96.0%).
- Under 1825.3%
- 18 to 6448.4%
- 65 and older26.3%
- White, not Hispanic96.0%
- Other or two or more3.9%
- Hispanic or Latino0.1%
- Black, not Hispanic0.0%
- Asian, not Hispanic0.0%
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 57231 earn?
Median household income is $78,646 (ACS 2020-2024), the 3rd highest of the 4 ranked ZIP codes in Kingsbury County. It is not measurably different from 2015-2019 ($84,473 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $78,646±$13,703
- Income per person
- $41,058
- Below the poverty line
- 8.8%
- Unemployed (of the labor force)
- 0.0%
- Adults 25+ with a bachelor's degree
- 24.8%
- Adjusted gross income per tax return, 2022
- $76,365800 returns; wages 54% 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 57231?
- Median home value (owners' estimate)
- $212,200
- Median gross rent
- $725
- Homes owned by their occupants
- 86.7%
- Housing units
- 877
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 57231?
77 business establishments had a location in this ZIP code in 2023, 11 more than in 2018; the most are in retail trade (ZIP Code Business Patterns).
- Retail trade14
- Construction11
- Other services (except public administration)10
- Health care and social assistance9
- Finance and insurance7
- Manufacturing6
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 57231?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 57249 | Lake Preston | 1,023 | $63k | 10.5 mi |
| 57353 | Iroquois | 812 | $76k | 12.5 mi |
| 57233 | Erwin | 350 | $83k | 12.9 mi |
| 57051 | Oldham | 163 | $56k | 15.8 mi |
| 57323 | Carthage | 126 | $51k | 16.1 mi |
| 57221 | Bryant | 1,158 | $74k | 17.5 mi |
| 57278 | Willow Lake | 1,011 | $70k | 19.5 mi |
| 57349 | Howard | 1,513 | $75k | 23.9 mi |
| 57214 | Badger | 162 | $65k | 20.4 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.