57233 ZIP Code — Erwin, SD

Kingsbury County, South Dakota

ZIP code 57233 is located in Erwin, South Dakota, within Kingsbury County. It covers approximately 36.73 square miles and serves a population of 257 residents. This is a standard ZIP code in the Central (CT) timezone, served by area code 605.

About ZIP code 57233

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 $275,000. Owner-occupancy is high at 86%, well above the national average.

The dominant occupation class is management, business, and professional, with agriculture and mining as the leading industry. The average commute of 17 minutes is near the national average.

College attainment at 18% is below the national average, consistent with a trades and production-oriented local economy.

20% of residents lack health insurance, above the national average.

Overall, ZIP code 57233 reflects a community defined by a trades-oriented workforce, high homeownership, and a significant Social Security-dependent population.

257

population

36.73

sq mi land

Standard

ZIP type

Central (CT)

timezone

57233 ZIP code map

Cities in ZIP code 57233

Below are the cities the US Postal Service accepts for ZIP code 57233. Using any city not on this list may result in mail delivery delays.

City	Status
Erwin	Acceptable

Demographics updated 05/2026

Population
Total population	257
Population density	7 / sq mi
State FIPS	46
County FIPS	077

Geography
Land area	36.73 sq mi
Water area	0.00 sq mi
Latitude	44.4925
Longitude	-97.3805
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	32.9%	37.0%	41.7%
$50k – $100k	15.8%	37.7%	33.8%
$100k – $200k	38.2%	21.3%	20.1%
Over $200k	13.2%	4.0%	4.4%

Demographics & statistics

257

Population

People per sq mi

20.6

Median age

Median household income

$39,991

Per capita income

$275,000

Median home value

Median monthly rent

86.4%

Home ownership

1.6%

Poverty rate

0.0%

Unemployment

Housing units

18.3%

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	101	39.3%
18 and over	156	60.7%
65 and over	32	12.5%
Median age	20.6 years

Race & ethnicity

White 100%

Group	Count	%
White	257	100%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	32.9%	37.0%	41.7%
$50k – $100k	15.8%	37.7%	33.8%
$100k – $200k	38.2%	21.3%	20.1%
Over $200k	13.2%	4.0%	4.4%

Under $10k 1.5%

$10k–$15k 1.5%

$15k–$25k 3.0%

$35k–$50k 9.1%

$50k–$75k 28.8%

$75k–$100k 6.1%

$100k–$150k 3.0%

$150k–$200k 27.3%

$200k+ 19.7%

Range	% of households
Under $10k	1.5%
$10k–$15k	1.5%
$15k–$25k	3.0%
$35k–$50k	9.1%
$50k–$75k	28.8%
$75k–$100k	6.1%
$100k–$150k	3.0%
$150k–$200k	27.3%
$200k+	19.7%
Median income	$0

Housing

Home values

Under $50k 15.8%

$50k–$100k 17.5%

$150k–$200k 3.5%

$200k–$300k 21.1%

$300k–$500k 42.1%

Housing overview

Metric	Value
Median home value	$275,000
Median rent / month	$0
Owner occupied	86.4%
Renter occupied	13.6%
Vacant	24.1%
Single-family detached	98.9%
Large apartment buildings	0.0%
Mobile homes	1.1%
Median rooms	8.1
Avg household size (owned)	4.35

Year built

Era	%
2020 or later	0.0%
2010–2019	3.4%
2000–2009	10.3%
1990–1999	8.0%
1980–1989	2.3%
1970–1979	3.4%
1960–1969	0.0%
1950–1959	4.6%
1940–1949	0.0%
1939 or earlier	67.8%

Bedrooms

Size	% of units
No bedroom (studio)	0.0%
1 bedroom	3.4%
2 bedrooms	4.6%
3 bedrooms	23.0%
4 bedrooms	14.9%
5+ bedrooms	54.0%

Vehicles per household

Vehicles	% of households
No vehicle	0.0%
1 vehicle	10.6%
2 vehicles	18.2%
3 or more	71.2%

Heating fuel

Fuel type	%
Utility gas	4.5%
Electricity	10.6%
Propane / LP gas	78.8%
Wood	6.1%

Households & families

Household type	Count	%
Married-couple family	45	68.2%
Cohabiting couple	5	7.6%
Male householder, no spouse	11	16.7%
Female householder, no spouse	5	7.6%
Households with children under 18	21	31.8%
Households with seniors (65+)	21	31.8%
Average household size	3.89

Marital status

Status	Male	Female
Never married	57.6%	8.5%
Married	38.1%	74.6%
Separated	0.0%	0.0%
Widowed	0.8%	13.6%
Divorced	3.4%	3.4%

Education

Less than 9th grade 0.0%

Some HS, no diploma 0.8%

HS graduate 52.5%

Some college, no degree 22.5%

Associate's degree 5.8%

Bachelor's degree 11.7%

Graduate / professional 6.7%

Metric	%
HS diploma or higher	99.2%
Bachelor's or higher	18.3%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	0	0.0%
Kindergarten	9	8.4%
Elementary school	57	53.3%
High school	21	19.6%
College / grad school	20	18.7%

Employment

Industry of employment

Agriculture & mining 35.7%

Construction 35.7%

Retail trade 10.7%

Education & healthcare 6.3%

Arts, food & hospitality 5.4%

Finance & real estate 4.5%

Manufacturing 1.8%

Occupation

Category	%
Management, business & arts	58.9%
Service	4.5%
Sales & office	10.7%
Natural resources & construction	23.2%
Production & transportation	2.7%

Employment type

Type	%
Private sector	85.7%
Government	0.9%
Self-employed	13.4%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	82.7%
Carpool	1.8%
Public transit	0.0%
Walk	5.5%
Work from home	10.0%
Other means	0.0%
Avg commute (minutes)	17.2

Poverty

All people 1.6%

Under 18 years 0.0%

18 and over 2.6%

Married-couple families 2.2%

Female-led households 0.0%

Income support

Source	% of households
Social Security	31.8%
Retirement income	6.1%
Supplemental Security	0.0%
Cash public assistance	0.0%
Food stamps / SNAP	0.0%

Health indicators

Condition	%
Obesity	33.6%
High blood pressure	38.9%
High cholesterol	37.2%
Diabetes	11.8%
Heart disease	9.7%
Stroke	4.1%
Asthma	8.2%
Arthritis	30.4%
Kidney disease	3.8%
Pulmonary disease	7.4%
Cancer	10.0%

Behavior / access	%
Smoking	15.7%
Binge drinking	15.9%
No physical activity	25.7%
Less than 7 hrs sleep	25.9%
Depression	13.3%
Fair or poor health	12.8%
Poor mental health	8.8%
Poor physical health	9.9%
No health insurance	10.8%
Visited doctor (checkup)	79.0%
Visited dentist	69.1%
Cholesterol screening	93.0%
Teeth loss	13.8%

Veterans & disability

Veterans	Count	%
Civilian veterans	9	5.8%

Disability	%
Any disability	3.1%
Under 18	0.0%
18–64 years	0.8%
65 and over	21.9%

Health insurance coverage

Type	%
Private insurance	63.8%
Public insurance	28.4%
No insurance	19.5%
Uninsured under 19	9.9%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	246	95.7%
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)	257	100.0%
Born in same state	257	100.0%
Born in different state	78	30.4%
Foreign born	0	0.0%
Naturalized citizen	0	0.0%
Not a US citizen	0	0.0%

Ancestry

Ancestry	Count	%
Arab	60	23.3%
Polish	38	14.8%
Italian	6	2.3%

Ancestry	Count	%
English	5	1.9%
French	5	1.9%

Technology access

Metric	% of households
Computer access	25.7%
Internet access	89.4%

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

Frequently asked questions about ZIP code 57233

What city is ZIP code 57233 in?

ZIP code 57233 is primarily assigned to Erwin, South Dakota.

What county is ZIP code 57233 in?

ZIP code 57233 falls within Kingsbury County, South Dakota.

Is ZIP code 57233 family-oriented?

39% of residents in ZIP code 57233 are under 18, reflecting a younger, family-oriented community.

Is ZIP code 57233 mostly owner-occupied?

86% of occupied units in ZIP code 57233 are owner-occupied, well above the national average.

What is the population of ZIP code 57233?

ZIP code 57233 has an estimated population of 257 residents, with a density of 7 people per square mile.

What is the typical home value in ZIP code 57233?

The median home value in ZIP code 57233 is $275,000.

What timezone is ZIP code 57233 in?

ZIP code 57233 observes the CST timezone.