ZipCodesToGo
South Dakota ZIP Codes
Harding County
Buffalo, SD
57720
57720 ZIP Code — Buffalo, SD
Harding County, South Dakota
ZIP code 57720 is located in
Buffalo ,
South Dakota ,
within Harding County .
It covers approximately 1,296.16 square miles and serves a population of
695 residents.
This is a standard ZIP code in the Mountain (MT) timezone,
served by area code 605 .
About ZIP code 57720
The housing stock consists of predominantly single-family detached homes. Most homes were built in the pre-1940, giving the area an established character. Median home value is $133,300. Owner-occupancy sits near the national average at 73%.
The gap between median ($72,031) and mean household income suggests income inequality — a small number of higher earners pull the average up. 32% of households receive Social Security income, suggesting a notable retiree or disability population.
The dominant occupation class is management, business, and professional, with agriculture and mining as the leading industry. The average commute of 11 minutes is near the national average. Remote work is prevalent — 30% of workers work from home.
Educational attainment is near the national average, with 27% of residents holding a bachelor's degree or higher.
Overall, ZIP code 57720 reflects a community defined by a high rate of remote workers and a significant Social Security-dependent population.
57720 ZIP code map
View map of 57720
Cities in ZIP code 57720
Below are the cities the US Postal Service accepts for ZIP code 57720. Using any city not on this list may result in mail delivery delays.
Demographics
updated 06/2026
Population
Total population
695
Population density
695 / sq mi
State FIPS
46
County FIPS
063
Geography
Land area
1,296.16 sq mi
Water area
4.19 sq mi
Latitude
45.5789
Longitude
-103.4989
Timezone
Mountain (MT)
Area code
605
Economics
updated 06/2026
Household income
Income range
This ZIP
County avg
State avg
Under $50k
24.9%
28.0%
41.7%
$50k – $100k
58.8%
53.5%
33.8%
$100k – $200k
14.9%
17.7%
20.1%
Over $200k
1.4%
0.8%
4.4%
Demographics & statistics
$72,031
Median household income
$133,300
Median home value
26.5%
Bachelor's or higher
Age distribution
Age summary
Group Count % Under 18 145 20.9% 18 and over 550 79.1% 65 and over 141 20.3% Median age 46.3 years
Race & ethnicity
American Indian / Alaska Native
1.1%
Group Count % White 597 84.7% Two or more races 84 11.9% Hispanic or Latino 10 1.4% American Indian / Alaska Native 8 1.1% Other race 6 0.9%
Household income
Income range
This ZIP
County avg
State avg
Under $50k
24.9%
28.0%
41.7%
$50k – $100k
58.8%
53.5%
33.8%
$100k – $200k
14.9%
17.7%
20.1%
Over $200k
1.4%
0.8%
4.4%
Range % of households $10k–$15k 5.6% $15k–$25k 3.1% $25k–$35k 1.9% $35k–$50k 13.0% $50k–$75k 28.3% $75k–$100k 18.0% $100k–$150k 14.3% $150k–$200k 8.4% $200k+ 7.5% Median income $72,031
Housing
Housing overview
Metric Value Median home value $133,300 Median rent / month $533 Owner occupied 73.3% Renter occupied 26.7% Vacant 28.4% Single-family detached 79.1% Large apartment buildings 0.0% Mobile homes 15.6% Median rooms 5.8 Avg household size (owned) 2.12
Year built
Era % 2020 or later 0.0% 2010–2019 8.7% 2000–2009 4.0% 1990–1999 6.4% 1980–1989 13.8% 1970–1979 13.1% 1960–1969 4.2% 1950–1959 13.6% 1940–1949 12.4% 1939 or earlier 23.8%
Bedrooms
Size % of units No bedroom (studio) 2.9% 1 bedroom 5.3% 2 bedrooms 22.4% 3 bedrooms 36.2% 4 bedrooms 22.2% 5+ bedrooms 10.9%
Vehicles per household
Vehicles % of households No vehicle 2.2% 1 vehicle 24.5% 2 vehicles 23.9% 3 or more 49.4%
Heating fuel
Fuel type % Utility gas 2.8% Electricity 25.5% Propane / LP gas 67.1% Fuel oil 0.9% Wood 1.9% No fuel used 1.6%
Households & families
Household type Count % Married-couple family 192 59.6% Cohabiting couple 16 5.0% Male householder, no spouse 65 20.2% Female householder, no spouse 49 15.2% Households with children under 18 82 25.5% Households with seniors (65+) 114 35.4% Average household size 2.16
Marital status
Status Male Female Never married 23.4% 16.3% Married 68.4% 64.1% Separated 2.6% 0.0% Widowed 1.0% 9.6% Divorced 4.6% 10.0%
Education
Some college, no degree
28.5%
Graduate / professional
5.5%
Metric % HS diploma or higher 94.7% Bachelor's or higher 26.5%
School enrollment (ages 3–17)
Type Count % Nursery / preschool 7 5.7% Kindergarten 17 13.8% Elementary school 51 41.5% High school 34 27.6% College / grad school 14 11.4%
Employment
Industry of employment
Agriculture & mining
40.7%
Transportation & utilities
6.9%
Education & healthcare
6.2%
Professional & management
5.3%
Public administration
3.8%
Arts, food & hospitality
3.3%
Finance & real estate
2.2%
Occupation
Category % Management, business & arts 49.0% Service 6.9% Sales & office 12.2% Natural resources & construction 16.5% Production & transportation 15.3%
Employment type
Type % Private sector 59.3% Government 11.5% Self-employed 27.3% Unpaid family workers 1.9%
Commute
Method % Drive alone 54.9% Carpool 7.1% Public transit 0.0% Walk 7.1% Work from home 30.0% Other means 1.0% Avg commute (minutes) 10.7
Poverty
Married-couple families
3.6%
Female-led households
18.8%
Income support
Source % of households Social Security 31.7% Retirement income 10.9% Supplemental Security 1.2% Cash public assistance 6.5% Food stamps / SNAP 0.9%
Health indicators
Condition % Obesity 33.0% High blood pressure 30.9% High cholesterol 31.1% Diabetes 8.7% Heart disease 6.6% Stroke 2.9% Asthma 8.7% Arthritis 23.5% Kidney disease 2.8% Pulmonary disease 5.8% Cancer 7.2%
Behavior / access % Smoking 17.3% Binge drinking 20.2% No physical activity 21.3% Less than 7 hrs sleep 27.6% Depression 15.2% Fair or poor health 10.7% Poor mental health 10.5% Poor physical health 8.6% No health insurance 11.3% Visited doctor (checkup) 74.5% Visited dentist 68.5% Cholesterol screening 89.3% Teeth loss 12.7%
Veterans & disability
Veterans Count % Civilian veterans 51 9.3%
Disability % Any disability 8.3% Under 18 2.1% 18–64 years 3.7% 65 and over 28.4%
Health insurance coverage
Type % Private insurance 84.3% Public insurance 34.8% No insurance 2.0% Uninsured under 19 0.0%
Language & origin
Language spoken at home (age 5+)
Language Count % English only 666 95.8% Spanish 0 0.0% Other Indo-European 0 0.0% Asian & Pacific Islander 0 0.0% Other languages 0 0.0%
Place of birth & citizenship
Origin Count % Native born (US) 682 98.1% Born in same state 675 97.1% Born in different state 416 59.9% Foreign born 7 1.0% Naturalized citizen 13 1.9% Not a US citizen 4 30.8%
Ancestry
Ancestry Count % Polish 176 25.3% Italian 97 14% French 47 6.8% Arab 22 3.2%
Ancestry Count % English 7 1% Dutch 7 1% German 1 0.1%
Technology access
Metric % of households Computer access 46.3% Internet access 93.2%
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 57720
What city is ZIP code 57720 in?
ZIP code 57720 is primarily assigned to Buffalo, South Dakota.
What county is ZIP code 57720 in?
ZIP code 57720 falls within Harding County, South Dakota.
What is the typical home value in ZIP code 57720?
The median home value in ZIP code 57720 is $133,300.
Does ZIP code 57720 have a large veteran population?
9% of civilians in ZIP code 57720 are veterans, above the national average of ~7%.
What is the population of ZIP code 57720?
ZIP code 57720 has an estimated population of 695 residents, with a density of 1 people per square mile.
What is the median household income in ZIP code 57720?
The median household income in ZIP code 57720 is $72,031, below the national median of ~$75,000.
What timezone is ZIP code 57720 in?
ZIP code 57720 observes the MST timezone.
Need the complete ZIP code database?
Download all 42,000+ US ZIP codes — Excel, CSV, or Access. Includes lat/lng, county FIPS & timezone.
Download database →
