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Where 57231 is
Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.
- 🔢 Type 57231 into a pocket calculator and turn it upside down: IEZLS — not quite a word, sorry.
- ➕ As a number, 57,231 = 3 × 3 × 6359. Its digits add up to 18, a total 2,332 other ZIP codes share.
- 💾In binary, the way a computer stores it:
1101111110001111 - 🏠 Its numerical neighbours: 57227 (Corona, SD, 81 mi away) and 57232 (Eden, SD, 87 mi away).
- 🔄 Backwards, 57231 becomes 13275, which is not a ZIP code at all.
- 👥 56 other ZIP codes are made of exactly the same digits (12537, 13752, 15237, 15327, 15723, 15732, …). The farthest-flung twin is 32751 in Maitland, FL, 1,407 miles away.
- 🧭 Farther north than 89% of all ZIP codes, and farther west than 76%.
- 🎯318 miles north of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 57231 and you would come out at 44.38°S, 82.42°E — 670 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
- ☀Longest day of the year: 15h 32m of daylight. Shortest: 8h 50m.
- 📏 At 249.3 square miles of land, 57231 is bigger than 93% of ZIP codes — room for about 189 Central Parks.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 1,724This ZIP1,724 |
|---|---|
| Households | 721This ZIP721 |
| Housing units | 877This ZIP877 |
| Median age | 44.2This ZIP44.2South Dakota38.0US 38.9 |
| Median household income | $78,646This ZIP$78,646South Dakota$75,081US $80,734 |
| Median home value | $212,200This ZIP$212,200South Dakota$257,400US $332,700 |
| Median gross rent | $725This ZIP$725South Dakota$946US $1,413 |
| Bachelor's degree or higher | 24.8%This ZIP24.8% |
| Mean commute | 13.5 minThis ZIP13.5 min |
| Population density | 6.9 / sq miThis ZIP6.9 / sq mi |
Business and tax activity
| Business establishments | 77This ZIP77 |
|---|---|
| Employees | 720This ZIP720 |
| Annual payroll | $37,019,000This ZIP$37,019,000 |
| Tax returns filed | 800This ZIP800 |
| Total adjusted gross income | $61,092,000This ZIP$61,092,000 |
Land area
| Land area | 249.28 sq miThis ZIP249.28 sq mi |
|---|---|
| Water area | 12.85 sq miThis ZIP12.85 sq mi |
Other place names in 57231
Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.
ZIP codes near 57231
| ZIP | City | Distance |
|---|---|---|
57249 | Lake Preston, SD | 10.5 mi |
57353 | Iroquois, SD | 12.5 mi |
57233 | Erwin, SD | 12.9 mi |
57051 | Oldham, SD | 15.8 mi |
57323 | Carthage, SD | 16.1 mi |
57221 | Bryant, SD | 17.5 mi |
57278 | Willow Lake, SD | 19.5 mi |
57214 | Badger, SD | 20.4 mi |
57212 | Arlington, SD | 21.9 mi |
57386 | Yale, SD | 22.4 mi |
Find every ZIP code within 10 miles of 57231 →
Questions about this ZIP code
Where is ZIP code 57231?
57231 is in De Smet, South Dakota, in Kingsbury County. Its published point location is 44.3758, -97.5823.
What county is 57231 in?
57231 lies in Kingsbury County.
What area code is 57231?
De Smet uses area code 605, from NANPA's telephone records.
What time zone is 57231 in?
57231 uses America/Chicago.
How many people live in 57231?
About 1,724 people live in ZIP code 57231, in 721 households, at 6.9 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.
What is the median household income in 57231?
$78,646 a year, against $75,081 across South Dakota.
What ZIP codes are near 57231?
The closest are 57249 (10.5 mi), 57353 (12.5 mi), 57233 (12.9 mi), 57051 (15.8 mi) and 57323 (16.1 mi).
Is 57231 a PO Box ZIP code?
57231 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “57231 ZIP Code — De Smet, South Dakota (Kingsbury County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/57231
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/57231.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.