57720 ZIP Code, Buffalo, SD
57720 is a ZIP code in Buffalo, South Dakota in Harding County. It covers 1,296 square miles of land. The closest ZIP codes are 57724 and 57776. 518 people live here in 264 households. It is rural, with fewer than 100 people per square mile, and most homes are owner-occupied (81%). Median household income is $79,091, close to the South Dakota median of $75,081; the median age is 52.3, older than most ZIP codes.
Quick facts
- Mailing city: Buffalo, SD
- County: Harding County
- Land area: 1,296 sq mi
- Population: 518
- Median household income: $79,091
- Carrier routes: 5 (149 homes)
Key figures
| Measure | Value |
|---|---|
| Residents | 518 |
| Households | 264 |
| Median household income | $79,091 |
| Income per person | $51,037 |
| Median age | 52.3 |
| Homeowners | 81.1% |
| Median home value | $157,000 |
| Median rent | $586 |
| Bachelor's degree or higher | 25.0% |
| Average commute (minutes) | 14 |
| Households with kids under 18 | 14.4% |
| Moved in the past year | 4.5% |
| Below the poverty line | 12.0% |
| Broadband internet | 90.5% |
| Speak a non-English language at home | 2.0% |
Household income
| % of households | Value |
|---|---|
| <$10K | 0.0% |
| $10–15K | 7.6% |
| $15–25K | 5.7% |
| $25–35K | 5.7% |
| $35–50K | 9.8% |
| $50–75K | 15.5% |
| $75–100K | 22.3% |
| $100–150K | 18.9% |
| $150–200K | 7.6% |
| $200K+ | 6.8% |
Age
| % of all residents | Value |
|---|---|
| <10 | 10.8% |
| 10–19 | 10.0% |
| 20–24 | 2.7% |
| 25–34 | 10.8% |
| 35–44 | 6.6% |
| 45–54 | 15.8% |
| 55–64 | 22.0% |
| 65–74 | 17.0% |
| 75+ | 4.3% |
Tenure
| % of housing units | Value |
|---|---|
| Owned, with mortgage | 19.8% |
| Owned outright | 36.8% |
| Rented | 13.2% |
| Vacant | 30.2% |
Type of building
| % of housing units | Value |
|---|---|
| Detached house | 74.3% |
| Townhome | 0.5% |
| 2–4 units | 2.9% |
| 5–19 units | 2.7% |
| 20+ units | 0.0% |
| Mobile / other | 19.5% |
Businesses in 57720
35 business establishments with 318 employees (ZIP Codes Business Patterns 2023).
- Construction: 6
- Retail Trade: 5
- Health Care and Social Assistance: 5
- Mining, Quarrying, and Oil and Gas Extraction: 4
- Professional, Scientific, and Technical Services: 4
- Other Services (except Public Administration): 3
EDDM carrier routes
57720 has 5 USPS carrier routes with 149 residential and 4 business mailboxes. Open the EDDM route map.
Carrier routes in 57720
57720 has 5 USPS carrier routes (5 highway contract (H)) with 149 residential and 4 business mailboxes. Routes range from 14 homes (H065) to 52 homes (H066); the median route has 21 homes. The Census counted 264 households in 57720 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.
| Homes per route | Routes |
|---|---|
| 1–249 | 5 |
| 250–499 | 0 |
| 500–749 | 0 |
| 750–999 | 0 |
| 1,000–1,499 | 0 |
| 1,500+ | 0 |
Best routes in 57720 for…
Most businesses
For B2B offers: office supplies, cleaning, IT, catering and commercial services.
- Route H067 — USPS business mailboxes 3, 46 homes
- Route H064 — USPS business mailboxes 1, 16 homes
Select these 2 routes on the route map
Every carrier route in 57720
| Route | Type | Homes | Businesses | Est. median income | Est. owners | Est. families with kids | Est. moved in past year |
|---|---|---|---|---|---|---|---|
| H063 | Highway contract | 21 | 0 | $71,419 | — | — | — |
| H064 | Highway contract | 16 | 1 | $71,419 | — | — | — |
| H065 | Highway contract | 14 | 0 | $71,419 | — | — | — |
| H066 | Highway contract | 52 | 0 | $71,419 | — | — | — |
| H067 | Highway contract | 46 | 3 | $71,419 | — | — | — |
Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 57720 on the EDDM route map.
How route demographics are estimated
Mailbox counts come from USPS; demographics are estimates
The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).
How a route gets its figures: the block-group length-share method
We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.
Margins of error
Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.
Different years
USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.
Why some routes show identical figures
Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.
Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.
Nearby ZIP codes
Areas that include 57720
- Buffalo, SD ZIP codes — 1 ZIP code
- Harding County ZIP codes — 10 ZIP codes
- South Dakota ZIP code data
Mail every home in 57720
Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.
EDDM guides
ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 57720, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.
Frequently asked questions
- What city is 57720 in?
- 57720 is a Buffalo, SD mailing address. None of its land lies inside a Census-defined city or community.
- What county is 57720 in?
- 57720 is in Harding County.
- What is the population of 57720?
- About 518 people (±86), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 752.
- What is the median household income in 57720?
- $79,091 (±$9,878), compared with $75,081 for South Dakota as a whole. Half the households in the ZIP code earn more and half earn less.
- How many carrier routes and mailboxes are in 57720?
- 5 USPS carrier routes with 149 residential and 4 business mailboxes (153 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
- What ZIP codes are near 57720?
- The closest, measured center to center: 57724 (20.2 mi, Camp Crook) and 57776 (21.1 mi).
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.