57365 ZIP Code — Oacoma, SD

Lyman County, South Dakota

ZIP code 57365 is located in Oacoma, South Dakota, within Lyman County. It covers approximately 62.47 square miles and serves a population of 522 residents. This is a standard ZIP code in the Central (CT) timezone, served by area code 605.

About ZIP code 57365

The housing stock consists of predominantly single-family detached homes. Most homes were built in the 2000s, giving the area an established character. Median home value is $208,300. Owner-occupancy is high at 79%, well above the national average.

Median household income is $68,750. The poverty rate of 3% is below the national average. 41% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 13 minutes is near the national average.

Educational attainment is near the national average, with 24% of residents holding a bachelor's degree or higher.

Notable community characteristics include a notable veteran presence at 13% of civilians, above the national average of 7%.

Overall, ZIP code 57365 reflects a community defined by a strong veteran community, high homeownership, and a significant Social Security-dependent population.

522

population

62.47

sq mi land

Standard

ZIP type

Central (CT)

timezone

57365 ZIP code map

Cities in ZIP code 57365

Below are the cities the US Postal Service accepts for ZIP code 57365. Using any city not on this list may result in mail delivery delays.

City	Status
Oacoma	Preferred

Nearby ZIP codes

57326 Chamberlain (3.8 mi) 57569 Reliance (8.4 mi) 57325 Chamberlain (8.9 mi) 57370 Pukwana (12.7 mi) 57339 Fort Thompson (18.3 mi)

Demographics updated 05/2026

Population
Total population	522
Population density	8 / sq mi
State FIPS	46
County FIPS	085

Geography
Land area	62.47 sq mi
Water area	9.53 sq mi
Latitude	43.8030
Longitude	-99.4062
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	31.8%	43.2%	41.7%
$50k – $100k	47.7%	40.1%	33.8%
$100k – $200k	20.5%	14.7%	20.1%
Over $200k	0.0%	2.0%	4.4%

Demographics & statistics

522

Population

People per sq mi

55.5

Median age

$68,750

Median household income

$39,237

Per capita income

$208,300

Median home value

$744

Median monthly rent

79.1%

Home ownership

3.1%

Poverty rate

4.5%

Unemployment

267

Housing units

23.6%

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	86	16.5%
18 and over	436	83.5%
65 and over	161	30.8%
Median age	55.5 years

Race & ethnicity

White 90.5%

American Indian / Alaska Native 3.5%

Hispanic or Latino 3%

Other race 3%

Group	Count	%
White	487	90.5%
American Indian / Alaska Native	19	3.5%
Hispanic or Latino	16	3%
Other race	16	3%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	31.8%	43.2%	41.7%
$50k – $100k	47.7%	40.1%	33.8%
$100k – $200k	20.5%	14.7%	20.1%
Over $200k	0.0%	2.0%	4.4%

Under $10k 2.0%

$15k–$25k 9.5%

$25k–$35k 11.9%

$35k–$50k 11.1%

$50k–$75k 21.7%

$75k–$100k 12.6%

$100k–$150k 19.4%

$150k–$200k 9.1%

$200k+ 2.8%

Range	% of households
Under $10k	2.0%
$15k–$25k	9.5%
$25k–$35k	11.9%
$35k–$50k	11.1%
$50k–$75k	21.7%
$75k–$100k	12.6%
$100k–$150k	19.4%
$150k–$200k	9.1%
$200k+	2.8%
Median income	$68,750

Housing

Home values

Under $50k 11.5%

$50k–$100k 7.0%

$100k–$150k 23.5%

$150k–$200k 7.0%

$200k–$300k 21.0%

$300k–$500k 23.0%

$500k–$1M 7.0%

Housing overview

Metric	Value
Median home value	$208,300
Median rent / month	$744
Owner occupied	79.1%
Renter occupied	20.9%
Vacant	20.9%
Single-family detached	70.3%
Large apartment buildings	0.0%
Mobile homes	18.8%
Median rooms	6.1
Avg household size (owned)	2.13

Year built

Era	%
2020 or later	1.9%
2010–2019	0.0%
2000–2009	30.3%
1990–1999	17.5%
1980–1989	12.5%
1970–1979	24.4%
1960–1969	5.6%
1950–1959	0.0%
1940–1949	0.6%
1939 or earlier	7.2%

Bedrooms

Size	% of units
No bedroom (studio)	0.0%
1 bedroom	2.5%
2 bedrooms	34.1%
3 bedrooms	40.9%
4 bedrooms	19.4%
5+ bedrooms	3.1%

Vehicles per household

Vehicles	% of households
No vehicle	6.3%
1 vehicle	23.3%
2 vehicles	32.0%
3 or more	38.3%

Heating fuel

Fuel type	%
Utility gas	6.3%
Electricity	52.6%
Propane / LP gas	40.3%
Fuel oil	0.8%

Households & families

Household type	Count	%
Married-couple family	145	57.3%
Cohabiting couple	4	1.6%
Male householder, no spouse	68	26.9%
Female householder, no spouse	36	14.2%
Households with children under 18	51	20.2%
Households with seniors (65+)	114	45.1%
Average household size	2.06

Marital status

Status	Male	Female
Never married	16.1%	22.6%
Married	60.7%	66.8%
Separated	7.9%	0.0%
Widowed	6.2%	5.1%
Divorced	9.1%	5.5%

Education

Less than 9th grade 1.2%

Some HS, no diploma 4.3%

HS graduate 48.6%

Some college, no degree 15.6%

Associate's degree 6.7%

Bachelor's degree 14.7%

Graduate / professional 8.9%

Metric	%
HS diploma or higher	94.5%
Bachelor's or higher	23.6%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	0	0.0%
Kindergarten	11	19.3%
Elementary school	13	22.8%
High school	23	40.4%
College / grad school	10	17.5%

Employment

Industry of employment

Education & healthcare 27.6%

Arts, food & hospitality 15.1%

Construction 11.5%

Public administration 10.4%

Retail trade 9.3%

Finance & real estate 8.6%

Professional & management 5.7%

Wholesale trade 3.9%

Other services 3.9%

Agriculture & mining 2.2%

Information 1.1%

Manufacturing 0.7%

Occupation

Category	%
Management, business & arts	40.1%
Service	21.5%
Sales & office	20.1%
Natural resources & construction	13.3%
Production & transportation	5.0%

Employment type

Type	%
Private sector	63.1%
Government	21.9%
Self-employed	15.1%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	63.7%
Carpool	11.7%
Public transit	0.0%
Walk	10.3%
Work from home	8.4%
Other means	5.9%
Avg commute (minutes)	12.8

Poverty

All people 3.1%

Under 18 years 0.0%

18 and over 3.7%

Married-couple families 0.0%

Female-led households 0.0%

Income support

Source	% of households
Social Security	41.1%
Retirement income	33.6%
Supplemental Security	2.8%
Cash public assistance	3.2%
Food stamps / SNAP	7.1%

Health indicators

Condition	%
Obesity	33.8%
High blood pressure	30.5%
High cholesterol	31.2%
Diabetes	9.0%
Heart disease	6.6%
Stroke	2.9%
Asthma	8.7%
Arthritis	23.7%
Kidney disease	2.8%
Pulmonary disease	5.7%
Cancer	7.1%

Behavior / access	%
Smoking	17.6%
Binge drinking	19.8%
No physical activity	21.2%
Less than 7 hrs sleep	27.7%
Depression	14.9%
Fair or poor health	10.7%
Poor mental health	10.3%
Poor physical health	8.6%
No health insurance	11.1%
Visited doctor (checkup)	75.3%
Visited dentist	69.0%
Cholesterol screening	90.0%
Teeth loss	12.1%

Veterans & disability

Veterans	Count	%
Civilian veterans	55	12.7%

Disability	%
Any disability	11.5%
Under 18	0.0%
18–64 years	2.6%
65 and over	32.9%

Health insurance coverage

Type	%
Private insurance	81.2%
Public insurance	37.7%
No insurance	5.4%
Uninsured under 19	0.0%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	497	95.2%
Spanish	16	3.2%
Other Indo-European	16	3.2%
Asian & Pacific Islander	0	0.0%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	506	96.9%
Born in same state	506	96.9%
Born in different state	373	71.5%
Foreign born	0	0.0%
Naturalized citizen	16	3.1%
Not a US citizen	0	0.0%

Ancestry

Ancestry	Count	%
Arab	73	14%
Italian	61	11.7%
Polish	49	9.4%
French	33	6.3%

Ancestry	Count	%
English	17	3.3%
Dutch	13	2.5%
German	5	1%

Technology access

Metric	% of households
Computer access	48.5%
Internet access	95.3%

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

Frequently asked questions about ZIP code 57365

What city is ZIP code 57365 in?

ZIP code 57365 is primarily assigned to Oacoma, South Dakota.

What county is ZIP code 57365 in?

ZIP code 57365 falls within Lyman County, South Dakota.

Does ZIP code 57365 have an older population?

31% of residents in ZIP code 57365 are 65 or older, above the national average of ~17%.

Does ZIP code 57365 have a large retiree population?

41% of households in ZIP code 57365 receive Social Security income, suggesting a significant retiree or disability population.

Does ZIP code 57365 have a large veteran population?

13% of civilians in ZIP code 57365 are veterans, above the national average of ~7%.

What is the population of ZIP code 57365?

ZIP code 57365 has an estimated population of 522 residents, with a density of 8 people per square mile.

What timezone is ZIP code 57365 in?

ZIP code 57365 observes the CST timezone.