57751 ZIP Code — Keystone, SD

Pennington County, South Dakota

ZIP code 57751 is located in Keystone, South Dakota, within Pennington County. It covers approximately 44.22 square miles and serves a population of 947 residents. This is a standard ZIP code in the Mountain (MT) timezone, served by area code 605.

About ZIP code 57751

The housing stock consists of a higher-than-average concentration of mobile homes. Most homes were built in the 2000s, giving the area an established character. Median home value is $357,100. Owner-occupancy is high at 84%, well above the national average.

Median household income is $98,393. The poverty rate of 6% is below the national average. 38% 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 31 minutes is near the national average.

Educational attainment is near the national average, with 44% of residents holding a bachelor's degree or higher.

Notable community characteristics include a notable veteran presence at 18% of civilians, above the national average of 7%.

Overall, ZIP code 57751 reflects a community defined by a strong veteran community, high homeownership, and a significant Social Security-dependent population.

947

population

44.22

sq mi land

Standard

ZIP type

Mountain (MT)

timezone

57751 ZIP code map

Cities in ZIP code 57751

Below are the cities the US Postal Service accepts for ZIP code 57751. Using any city not on this list may result in mail delivery delays.

City	Status
Keystone	Preferred

Nearby ZIP codes

57702 Rapid City (8.8 mi) 57744 Hermosa (15.7 mi) 57745 Hill City (18.9 mi) 57738 Fairburn (19.6 mi) 57730 Custer (19.9 mi)

Demographics updated 08/2026

Population
Total population	947
Population density	21 / sq mi
State FIPS	46
County FIPS	103

Geography
Land area	44.22 sq mi
Water area	0.01 sq mi
Latitude	43.8852
Longitude	-103.4291
Timezone	Mountain (MT)
Area code	605

Total population by age

Gender

Race & ethnicity

Economics updated 08/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	36.9%	42.3%	41.7%
$50k – $100k	29.7%	33.3%	33.8%
$100k – $200k	29.2%	19.2%	20.1%
Over $200k	4.2%	5.2%	4.4%

Demographics & statistics

947

Population

People per sq mi

55.5

Median age

$98,393

Median household income

$42,910

Per capita income

$357,100

Median home value

$561

Median monthly rent

84.1%

Home ownership

6.2%

Poverty rate

3.4%

Unemployment

415

Housing units

43.8%

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	20.1%
18 and over	757	79.9%
65 and over	198	20.9%
Median age	55.5 years

Race & ethnicity

White 91.4%

Two or more races 3.9%

Hispanic or Latino 2.9%

Asian 0.8%

American Indian / Alaska Native 0.8%

Other race 0.2%

Group	Count	%
White	891	91.4%
Two or more races	38	3.9%
Hispanic or Latino	28	2.9%
Asian	8	0.8%
American Indian / Alaska Native	8	0.8%
Other race	2	0.2%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	36.9%	42.3%	41.7%
$50k – $100k	29.7%	33.3%	33.8%
$100k – $200k	29.2%	19.2%	20.1%
Over $200k	4.2%	5.2%	4.4%

$10k–$15k 2.5%

$15k–$25k 5.8%

$25k–$35k 5.8%

$35k–$50k 10.9%

$50k–$75k 14.5%

$75k–$100k 11.7%

$100k–$150k 32.6%

$150k–$200k 11.4%

$200k+ 4.7%

Range	% of households
$10k–$15k	2.5%
$15k–$25k	5.8%
$25k–$35k	5.8%
$35k–$50k	10.9%
$50k–$75k	14.5%
$75k–$100k	11.7%
$100k–$150k	32.6%
$150k–$200k	11.4%
$200k+	4.7%
Median income	$98,393

Housing

Home values

Under $50k 12.3%

$50k–$100k 3.3%

$100k–$150k 0.7%

$150k–$200k 6.6%

$200k–$300k 20.5%

$300k–$500k 18.2%

$500k–$1M 34.8%

$1M+ 3.6%

Housing overview

Metric	Value
Median home value	$357,100
Median rent / month	$561
Owner occupied	84.1%
Renter occupied	15.9%
Vacant	23.9%
Single-family detached	62.9%
Large apartment buildings	0.0%
Mobile homes	19.5%
Median rooms	4.4
Avg household size (owned)	2.64

Year built

Era	%
2020 or later	0.0%
2010–2019	4.9%
2000–2009	29.4%
1990–1999	16.1%
1980–1989	13.6%
1970–1979	13.8%
1960–1969	3.8%
1950–1959	7.6%
1940–1949	0.0%
1939 or earlier	10.8%

Bedrooms

Size	% of units
No bedroom (studio)	0.0%
1 bedroom	11.9%
2 bedrooms	31.4%
3 bedrooms	41.5%
4 bedrooms	13.1%
5+ bedrooms	2.1%

Vehicles per household

Vehicles	% of households
No vehicle	1.7%
1 vehicle	4.7%
2 vehicles	28.7%
3 or more	64.9%

Heating fuel

Fuel type	%
Utility gas	7.0%
Electricity	32.6%
Propane / LP gas	36.5%
Fuel oil	0.3%
Wood	23.1%

Households & families

Household type	Count	%
Married-couple family	270	75.2%
Cohabiting couple	25	7.0%
Male householder, no spouse	33	9.2%
Female householder, no spouse	31	8.6%
Households with children under 18	140	39.0%
Households with seniors (65+)	120	33.4%
Average household size	2.59

Marital status

Status	Male	Female
Never married	13.3%	26.4%
Married	72.3%	61.9%
Separated	0.0%	0.0%
Widowed	0.0%	1.2%
Divorced	14.3%	10.6%

Education

Less than 9th grade 1.4%

Some HS, no diploma 5.3%

HS graduate 29.2%

Some college, no degree 10.6%

Associate's degree 9.7%

Bachelor's degree 18.5%

Graduate / professional 25.3%

Metric	%
HS diploma or higher	93.3%
Bachelor's or higher	43.8%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	7	4.0%
Kindergarten	10	5.6%
Elementary school	66	37.3%
High school	74	41.8%
College / grad school	20	11.3%

Employment

Industry of employment

Education & healthcare 27.3%

Retail trade 20.9%

Arts, food & hospitality 15.5%

Construction 10.3%

Transportation & utilities 7.5%

Public administration 6.5%

Professional & management 4.5%

Agriculture & mining 4.3%

Other services 1.7%

Finance & real estate 0.9%

Manufacturing 0.2%

Wholesale trade 0.2%

Information 0.2%

Occupation

Category	%
Management, business & arts	33.6%
Service	21.9%
Sales & office	20.6%
Natural resources & construction	16.3%
Production & transportation	7.7%

Employment type

Type	%
Private sector	68.4%
Government	25.0%
Self-employed	5.8%
Unpaid family workers	0.7%

Commute

Method	%
Drive alone	69.8%
Carpool	9.2%
Public transit	0.0%
Walk	13.0%
Work from home	4.0%
Other means	4.0%
Avg commute (minutes)	30.8

Poverty

All people 6.2%

Under 18 years 4.9%

18 and over 6.5%

Married-couple families 1.9%

Female-led households 16.0%

Income support

Source	% of households
Social Security	38.4%
Retirement income	28.7%
Supplemental Security	1.1%
Cash public assistance	0.3%
Food stamps / SNAP	7.0%

Health indicators

Condition	%
Obesity	31.5%
High blood pressure	33.5%
High cholesterol	36.7%
Diabetes	9.3%
Heart disease	6.9%
Stroke	2.8%
Asthma	8.4%
Arthritis	26.6%
Kidney disease	2.8%
Pulmonary disease	5.4%
Cancer	8.1%

Behavior / access	%
Smoking	14.3%
Binge drinking	17.3%
No physical activity	18.5%
Less than 7 hrs sleep	25.4%
Depression	15.1%
Fair or poor health	9.7%
Poor mental health	9.1%
Poor physical health	8.0%
No health insurance	8.8%
Visited doctor (checkup)	77.3%
Visited dentist	72.4%
Cholesterol screening	92.8%
Teeth loss	9.6%

Veterans & disability

Veterans	Count	%
Civilian veterans	136	18.0%

Disability	%
Any disability	7.5%
Under 18	0.0%
18–64 years	3.0%
65 and over	27.3%

Health insurance coverage

Type	%
Private insurance	67.3%
Public insurance	30.4%
No insurance	14.7%
Uninsured under 19	4.7%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	907	95.8%
Spanish	44	4.9%
Other Indo-European	37	4.1%
Asian & Pacific Islander	7	0.8%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	898	94.8%
Born in same state	890	94.0%
Born in different state	389	41.1%
Foreign born	8	0.8%
Naturalized citizen	49	5.2%
Not a US citizen	32	65.3%

Ancestry

Ancestry	Count	%
French	174	18.4%
Polish	102	10.8%
Italian	93	9.8%

Ancestry	Count	%
Arab	22	2.3%
Dutch	5	0.5%
Irish	4	0.4%

Technology access

Metric	% of households
Computer access	37.9%
Internet access	97.5%

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

Frequently asked questions about ZIP code 57751

What city is ZIP code 57751 in?

ZIP code 57751 is primarily assigned to Keystone, South Dakota.

What county is ZIP code 57751 in?

ZIP code 57751 falls within Pennington County, South Dakota.

Is ZIP code 57751 mostly owner-occupied?

84% of occupied units in ZIP code 57751 are owner-occupied, well above the national average.

Does ZIP code 57751 have a large veteran population?

18% of civilians in ZIP code 57751 are veterans, above the national average of ~7%.

Does ZIP code 57751 have a large retiree population?

38% of households in ZIP code 57751 receive Social Security income, suggesting a significant retiree or disability population.

What is the typical home value in ZIP code 57751?

The median home value in ZIP code 57751 is $357,100.

What timezone is ZIP code 57751 in?

ZIP code 57751 observes the MST timezone.