57266 ZIP Code — Summit, SD

Roberts County, South Dakota

ZIP code 57266 is located in Summit, South Dakota, within Roberts County. It covers approximately 127.26 square miles and serves a population of 571 residents. This is a standard ZIP code in the Central (CT) timezone, served by area code 605.

About ZIP code 57266

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 $103,800. Owner-occupancy sits near the national average at 73%.

Median household income is $62,292. Poverty affects 21% of residents, above the national average.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 25 minutes is near the national average.

College attainment at 15% is below the national average, consistent with a trades and production-oriented local economy.

Health indicators show elevated rates of smoking (24%) compared to national benchmarks.

Overall, ZIP code 57266 reflects a community defined by a trades-oriented workforce and economic challenges above the national average.

571

population

127.26

sq mi land

Standard

ZIP type

Central (CT)

timezone

57266 ZIP code map

Cities in ZIP code 57266

Below are the cities the US Postal Service accepts for ZIP code 57266. Using any city not on this list may result in mail delivery delays.

City	Status
Summit	Preferred

Nearby ZIP codes

57251 Marvin (7 mi) 57273 Waubay (10.2 mi) 57263 South Shore (11.6 mi) 57257 Peever (13.6 mi) 57279 Wilmot (13.9 mi) 57269 Twin Brooks (14.7 mi) 57239 Grenville (18.7 mi) 57264 Stockholm (19.5 mi)

Demographics updated 05/2026

Population
Total population	571
Population density	4 / sq mi
State FIPS	46
County FIPS	109

Geography
Land area	127.26 sq mi
Water area	1.45 sq mi
Latitude	45.3112
Longitude	-97.0873
Timezone	Central (CT)
Area code	605

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	42.6%	50.2%	41.7%
$50k – $100k	43.1%	32.4%	33.8%
$100k – $200k	12.4%	14.7%	20.1%
Over $200k	2.0%	2.7%	4.4%

Demographics & statistics

571

Population

People per sq mi

30.2

Median age

$62,292

Median household income

$25,702

Per capita income

$103,800

Median home value

$708

Median monthly rent

73.3%

Home ownership

21.2%

Poverty rate

3.8%

Unemployment

184

Housing units

14.9%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

10–14

15–19

20–24

25–34

35–44

45–54

55–59

60–64

65–74

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	190	33.3%
18 and over	381	66.7%
65 and over	61	10.7%
Median age	30.2 years

Race & ethnicity

White 77%

American Indian / Alaska Native 16.2%

Two or more races 3.1%

Hispanic or Latino 1.4%

Other race 1.2%

Black or African American 0.5%

Asian 0.5%

Group	Count	%
White	446	77%
American Indian / Alaska Native	94	16.2%
Two or more races	18	3.1%
Hispanic or Latino	8	1.4%
Other race	7	1.2%
Black or African American	3	0.5%
Asian	3	0.5%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	42.6%	50.2%	41.7%
$50k – $100k	43.1%	32.4%	33.8%
$100k – $200k	12.4%	14.7%	20.1%
Over $200k	2.0%	2.7%	4.4%

Under $10k 4.7%

$10k–$15k 7.9%

$15k–$25k 5.2%

$25k–$35k 12.6%

$35k–$50k 9.4%

$50k–$75k 16.8%

$75k–$100k 14.1%

$100k–$150k 23.6%

$150k–$200k 1.6%

$200k+ 4.2%

Range	% of households
Under $10k	4.7%
$10k–$15k	7.9%
$15k–$25k	5.2%
$25k–$35k	12.6%
$35k–$50k	9.4%
$50k–$75k	16.8%
$75k–$100k	14.1%
$100k–$150k	23.6%
$150k–$200k	1.6%
$200k+	4.2%
Median income	$62,292

Housing

Home values

Under $50k 15.0%

$50k–$100k 33.6%

$100k–$150k 10.7%

$150k–$200k 7.9%

$200k–$300k 9.3%

$300k–$500k 17.1%

$500k–$1M 3.6%

$1M+ 2.9%

Housing overview

Metric	Value
Median home value	$103,800
Median rent / month	$708
Owner occupied	73.3%
Renter occupied	26.7%
Vacant	18.7%
Single-family detached	88.5%
Large apartment buildings	0.0%
Mobile homes	7.7%
Median rooms	6.2
Avg household size (owned)	3.03

Year built

Era	%
2020 or later	0.0%
2010–2019	3.0%
2000–2009	8.9%
1990–1999	4.7%
1980–1989	6.4%
1970–1979	14.5%
1960–1969	5.1%
1950–1959	3.8%
1940–1949	11.9%
1939 or earlier	41.7%

Bedrooms

Size	% of units
No bedroom (studio)	0.9%
1 bedroom	7.2%
2 bedrooms	18.7%
3 bedrooms	42.6%
4 bedrooms	23.0%
5+ bedrooms	7.7%

Vehicles per household

Vehicles	% of households
No vehicle	2.1%
1 vehicle	21.5%
2 vehicles	27.7%
3 or more	48.7%

Heating fuel

Fuel type	%
Utility gas	3.1%
Electricity	37.2%
Propane / LP gas	51.8%
Fuel oil	4.7%
Wood	2.1%

Households & families

Household type	Count	%
Married-couple family	109	57.1%
Cohabiting couple	7	3.7%
Male householder, no spouse	39	20.4%
Female householder, no spouse	36	18.8%
Households with children under 18	72	37.7%
Households with seniors (65+)	50	26.2%
Average household size	2.99

Marital status

Status	Male	Female
Never married	36.4%	21.3%
Married	50.4%	61.2%
Separated	0.0%	0.0%
Widowed	1.3%	11.8%
Divorced	11.8%	5.6%

Education

Less than 9th grade 4.1%

Some HS, no diploma 4.8%

HS graduate 37.8%

Some college, no degree 18.1%

Associate's degree 20.3%

Bachelor's degree 12.1%

Graduate / professional 2.9%

Metric	%
HS diploma or higher	91.1%
Bachelor's or higher	14.9%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	24	14.6%
Kindergarten	7	4.3%
Elementary school	82	50.0%
High school	46	28.0%
College / grad school	5	3.0%

Employment

Industry of employment

Education & healthcare 24.9%

Agriculture & mining 17.3%

Retail trade 13.4%

Construction 10.5%

Manufacturing 9.7%

Arts, food & hospitality 7.6%

Finance & real estate 5.1%

Transportation & utilities 2.9%

Other services 2.9%

Public administration 2.5%

Wholesale trade 2.2%

Professional & management 0.7%

Information 0.4%

Occupation

Category	%
Management, business & arts	44.0%
Service	16.2%
Sales & office	15.5%
Natural resources & construction	11.2%
Production & transportation	13.0%

Employment type

Type	%
Private sector	65.7%
Government	19.1%
Self-employed	13.7%
Unpaid family workers	1.4%

Commute

Method	%
Drive alone	79.2%
Carpool	4.4%
Public transit	0.0%
Walk	6.9%
Work from home	9.5%
Other means	0.0%
Avg commute (minutes)	24.7

Poverty

All people 21.2%

Under 18 years 27.4%

18 and over 18.1%

Married-couple families 11.0%

Female-led households 22.2%

Income support

Source	% of households
Social Security	27.7%
Retirement income	11.5%
Supplemental Security	1.6%
Cash public assistance	0.5%
Food stamps / SNAP	8.4%

Health indicators

Condition	%
Obesity	39.2%
High blood pressure	33.1%
High cholesterol	30.1%
Diabetes	11.0%
Heart disease	7.7%
Stroke	3.8%
Asthma	9.7%
Arthritis	24.5%
Kidney disease	3.3%
Pulmonary disease	7.9%
Cancer	6.4%

Behavior / access	%
Smoking	24.2%
Binge drinking	20.3%
No physical activity	29.0%
Less than 7 hrs sleep	30.6%
Depression	16.2%
Fair or poor health	15.7%
Poor mental health	12.3%
Poor physical health	11.2%
No health insurance	15.5%
Visited doctor (checkup)	74.3%
Visited dentist	61.1%
Cholesterol screening	86.2%
Teeth loss	20.0%

Veterans & disability

Veterans	Count	%
Civilian veterans	27	7.1%

Disability	%
Any disability	4.4%
Under 18	1.6%
18–64 years	2.8%
65 and over	21.3%

Health insurance coverage

Type	%
Private insurance	66.7%
Public insurance	25.9%
No insurance	13.3%
Uninsured under 19	11.0%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	508	89.0%
Spanish	13	2.6%
Other Indo-European	2	0.4%
Asian & Pacific Islander	6	1.2%
Other languages	3	0.6%

Place of birth & citizenship

Origin	Count	%
Native born (US)	566	99.1%
Born in same state	564	98.8%
Born in different state	459	80.4%
Foreign born	2	0.4%
Naturalized citizen	5	0.9%
Not a US citizen	3	60.0%

Ancestry

Ancestry	Count	%
Polish	77	13.5%
Italian	37	6.5%
English	14	2.5%

Ancestry	Count	%
French	6	1.1%
Arab	6	1.1%
Dutch	3	0.5%

Technology access

Metric	% of households
Computer access	33.5%
Internet access	90.1%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 57266

What city is ZIP code 57266 in?

ZIP code 57266 is primarily assigned to Summit, South Dakota.

What county is ZIP code 57266 in?

ZIP code 57266 falls within Grant County, South Dakota.

Is ZIP code 57266 family-oriented?

33% of residents in ZIP code 57266 are under 18, reflecting a younger, family-oriented community.

What is the poverty rate in ZIP code 57266?

21% of residents in ZIP code 57266 live below the poverty line, above the national average.

How educated is the population of ZIP code 57266?

15% of residents hold a bachelor's degree or higher — below the national average of ~33%, consistent with a trades-oriented local economy.

What is the typical home value in ZIP code 57266?

The median home value in ZIP code 57266 is $103,800.

What timezone is ZIP code 57266 in?

ZIP code 57266 observes the CST timezone.