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zipcodes.pro — ZIP/57751

57751

ZIP 57751 is Keystone, South Dakota, mostly in Pennington County; area code 605; Mountain time.

Type
Standard
Time zone
America/Denver
County
Pennington +1 more
Metro area
Rapid City, SD
Population
893
Coordinates
43.8691, -103.4269
☼ Live from 57751 — Keystone, SD

Weather right now

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Local time: —

Where 57751 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.

★ Weird and wonderful facts about 57751
  • 🔢 Type 57751 into a pocket calculator and turn it upside down: ISLLS — not quite a word, sorry.
  • ➕ 57751 is a prime number. It cannot be divided by anything except 1 and itself. Its digits add up to 25, a total 2,242 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 1110000110010111
  • 🏠 Its numerical neighbours: 57750 (Interior, SD, 76 mi away) and 57752 (Kyle, SD, 68 mi away).
  • 🔄 Backwards, 57751 becomes 15775 — and that is a real ZIP code: Spangler, PA, 1,275 miles away.
  • 👥 13 other ZIP codes are made of exactly the same digits (15757, 15775, 17557, 17575, 51577, 55717, …). The farthest-flung twin is 17557 in New Holland, PA, 1,422 miles away.
  • 🧭 Farther north than 87% of all ZIP codes, and farther west than 82%.
  • 🎯374 miles northwest of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 57751 and you would come out at 43.87°S, 76.57°E — 484 miles from Port-aux-Français, French Southern Territories, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 28m of daylight. Shortest: 8h 54m.
  • 📏 At 44.2 square miles of land, 57751 is bigger than 56% of ZIP codes — room for about 34 Central Parks.
🌙 The sky over 57751 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population893This ZIP893
Households327This ZIP327
Housing units477This ZIP477
Median age54.2This ZIP54.2South Dakota38.0US 38.9
Median household income$97,969This ZIP$97,969South Dakota$75,081US $80,734
Median home value$473,500This ZIP$473,500South Dakota$257,400US $332,700
Median gross rent$600This ZIP$600South Dakota$946US $1,413
Bachelor's degree or higher43.0%This ZIP43.0%
Mean commute34.2 minThis ZIP34.2 min
Population density20.2 / sq miThis ZIP20.2 / sq mi

Business and tax activity

Business establishments72This ZIP72
Employees304This ZIP304
Annual payroll$18,744,000This ZIP$18,744,000
Tax returns filed560This ZIP560
Total adjusted gross income$39,727,000This ZIP$39,727,000

Land area

Land area44.22 sq miThis ZIP44.22 sq mi
Water area0.01 sq miThis ZIP0.01 sq mi

Counties 57751 spans

A ZIP code is a mail route and ignores county lines. Shares are by overlapping land area.

CountyShare of this ZIP
Pennington County 66.6%
Custer County 33.4%

Other place names in 57751

Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.

ZIP codes near 57751

ZIPCityDistance
57702 Rapid City, SD 11.3 mi
57730 Custer, SD 14.8 mi
57709 Rapid City, SD 15.3 mi
57738 Fairburn, SD 18.5 mi
57744 Hermosa, SD 20.3 mi
57745 Hill City, SD 20.4 mi
57773 Pringle, SD 20.7 mi
57701 Rapid City, SD 20.8 mi
57718 Black Hawk, SD 21.0 mi
57703 Rapid City, SD 21.3 mi

Find every ZIP code within 10 miles of 57751 →

Questions about this ZIP code

Where is ZIP code 57751?

57751 is in Keystone, South Dakota, in Pennington County, part of the Rapid City, SD metropolitan area. Its published point location is 43.8691, -103.4269.

What county is 57751 in?

57751 spans 2 counties: Pennington County and Custer County. Most of it falls in Pennington County, measured by overlapping land area — the county holding the most land in a ZIP code is not always the one holding the most residents.

What area code is 57751?

Keystone uses area code 605, from NANPA's telephone records.

What time zone is 57751 in?

57751 uses America/Denver.

How many people live in 57751?

About 893 people live in ZIP code 57751, in 327 households, at 20.2 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 57751?

$97,969 a year, against $75,081 across South Dakota.

What ZIP codes are near 57751?

The closest are 57702 (11.3 mi), 57730 (14.8 mi), 57709 (15.3 mi), 57738 (18.5 mi) and 57744 (20.3 mi).

Is 57751 a PO Box ZIP code?

57751 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “57751 ZIP Code — Keystone, South Dakota (Pennington County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/57751

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