Alton ZIP Codes — Sioux County, IA

There is one unique ZIP code in Alton, Iowa and it is 51003. Area code: 712.

ZIP codes

54.36

sq mi land

0.03

sq mi water

712

area code

Alton, IA ZIP code map

About Alton, IA

Alton, Iowa, is a quaint city located within the picturesque confines of Sioux County. Known for its strong sense of community and serene environment, Alton offers a peaceful lifestyle for its residents. Despite its small size, this charming town encompasses rich cultural heritage and a friendly atmosphere.

Location & geography

Situated in the northwestern part of Iowa, Alton is surrounded by lush farmland and rolling landscapes. The city has the ZIP code 51003 and is approximately 10 miles southwest of the larger city of Sioux Center, 15 miles northeast of Orange City, and about 20 miles north of Sheldon. Covering a land area of 54.36 square miles and a small water area of 0.03 square miles, Alton features a predominantly rural terrain.

Community & economy

The character of Alton is defined by its close-knit community and actively engaged residents. The local economy is primarily driven by agriculture, with many families involved in farming and related industries. Daily life in Alton revolves around community events, local schools, and a family-friendly environment.

Transportation

Alton is accessible via State Highway 10, making it convenient for residents to commute to nearby towns and cities. The nearest regional airport is the Sioux Gateway Airport, located about 30 miles to the east in Sioux City, Iowa. Public transportation options are limited, so most residents rely on personal vehicles for daily travel.

History

Founded in the late 19th century, Alton has a rich history tied to the development of Sioux County and the surrounding agricultural lands. Key industries have traditionally revolved around farming and agriculture, which remain vital to the local economy. Notable events in the town's history include its founding in 1882 and the establishment of various community organizations that continue to foster growth and connection among residents.

Did you know?

One surprising fact about Alton is that it is known for hosting an annual Dutch Heritage Festival, celebrating its strong Dutch roots and culture. Additionally, Alton has distinct architectural influences from its early settlers, which can still be seen in the town's historical buildings.

ZIP codes for Alton, IA (1)

ZIP code	City	County	Map
51003	Alton	Sioux	View map

Demographics & statistics

1,761

Population

35.0

Median age

$85,536

Median household income

$39,844

Per capita income

$215,800

Median home value

$695

Median monthly rent

88.4%

Home ownership

1.9%

Poverty rate

1.8%

Unemployment

654

Housing units

23.7%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

10–14

15–19

102

20–24

107

25–34

101

35–44

45–54

55–59

60–64

65–74

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	421	23.9%
18 and over	1,340	76.1%
65 and over	291	16.5%
Median age	35.0 years

Race & ethnicity

White 95.8%

Two or more races 2%

Hispanic or Latino 1%

Asian 0.8%

Black or African American 0.2%

Other race 0.2%

Group	Count	%
White	1,704	95.8%
Two or more races	35	2%
Hispanic or Latino	18	1%
Asian	15	0.8%
Black or African American	4	0.2%
Other race	3	0.2%

Household income

Under $10k 0.7%

$10k–$15k 1.5%

$15k–$25k 2.4%

$25k–$35k 7.6%

$35k–$50k 12.8%

$50k–$75k 15.8%

$75k–$100k 16.5%

$100k–$150k 30.4%

$150k–$200k 4.9%

$200k+ 7.4%

Range	% of households
Under $10k	0.7%
$10k–$15k	1.5%
$15k–$25k	2.4%
$25k–$35k	7.6%
$35k–$50k	12.8%
$50k–$75k	15.8%
$75k–$100k	16.5%
$100k–$150k	30.4%
$150k–$200k	4.9%
$200k+	7.4%
Median income	$85,536

Housing

Home values

Under $50k 4.2%

$50k–$100k 15.0%

$100k–$150k 15.0%

$150k–$200k 10.4%

$200k–$300k 24.2%

$300k–$500k 27.4%

$500k–$1M 3.7%

Housing overview

Metric	Value
Median home value	$215,800
Median rent / month	$695
Owner occupied	88.4%
Renter occupied	11.6%
Vacant	8.2%
Single-family detached	84.7%
Large apartment buildings	0.0%
Mobile homes	1.8%
Median rooms	7.5
Avg household size (owned)	2.79

Year built

Era	%
2020 or later	0.0%
2010–2019	5.7%
2000–2009	9.3%
1990–1999	8.6%
1980–1989	5.1%
1970–1979	21.6%
1960–1969	15.2%
1950–1959	4.9%
1940–1949	2.6%
1939 or earlier	27.0%

Bedrooms

Size	% of units
No bedroom (studio)	2.2%
1 bedroom	4.0%
2 bedrooms	15.6%
3 bedrooms	32.8%
4 bedrooms	34.4%
5+ bedrooms	11.1%

Vehicles per household

Vehicles	% of households
No vehicle	0.4%
1 vehicle	24.4%
2 vehicles	42.6%
3 or more	32.6%

Heating fuel

Fuel type	%
Utility gas	43.6%
Electricity	47.6%
Propane / LP gas	6.1%
Wood	0.6%

Households & families

Household type	Count	%
Married-couple family	479	71.3%
Cohabiting couple	52	7.7%
Male householder, no spouse	78	11.6%
Female householder, no spouse	63	9.4%
Households with children under 18	198	29.5%
Households with seniors (65+)	186	27.7%
Average household size	2.62

Marital status

Status	Male	Female
Never married	28.8%	19.7%
Married	66.6%	72.5%
Separated	1.4%	1.4%
Widowed	1.2%	5.3%
Divorced	1.9%	1.1%

Education

Less than 9th grade 1.9%

Some HS, no diploma 3.8%

HS graduate 31.1%

Some college, no degree 26.3%

Associate's degree 13.1%

Bachelor's degree 19.7%

Graduate / professional 4.1%

Metric	%
HS diploma or higher	94.2%
Bachelor's or higher	23.7%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	42	12.3%
Kindergarten	26	7.6%
Elementary school	124	36.3%
High school	103	30.1%
College / grad school	47	13.7%

Employment

Industry of employment

Education & healthcare 21.9%

Manufacturing 15.7%

Retail trade 14.6%

Construction 8.3%

Agriculture & mining 7.8%

Finance & real estate 6.9%

Public administration 5.1%

Professional & management 4.7%

Transportation & utilities 4.4%

Other services 4.4%

Information 2.8%

Arts, food & hospitality 2.6%

Wholesale trade 0.6%

Occupation

Category	%
Management, business & arts	46.6%
Service	10.5%
Sales & office	12.4%
Natural resources & construction	18.3%
Production & transportation	12.1%

Employment type

Type	%
Private sector	72.9%
Government	14.0%
Self-employed	12.8%
Unpaid family workers	0.2%

Commute

Method	%
Drive alone	82.6%
Carpool	8.5%
Public transit	0.5%
Walk	0.5%
Other means	1.3%
Avg commute (minutes)	13.3

Poverty

All people 1.9%

Under 18 years 2.9%

18 and over 1.6%

Married-couple families 0.0%

Female-led households 48.0%

Income support

Source	% of households
Social Security	29.8%
Retirement income	23.2%
Supplemental Security	6.4%
Cash public assistance	2.1%
Food stamps / SNAP	2.2%

Health indicators

Condition	%
High blood pressure	30.6%
High cholesterol	30.3%
Heart disease	5.4%
Stroke	2.5%
Asthma	8.8%
Arthritis	22.2%
Kidney disease	2.4%
Pulmonary disease	5.5%
Cancer	6.3%

Behavior / access	%
Binge drinking	21.1%
No physical activity	21.8%
Less than 7 hrs sleep	28.6%
Fair or poor health	10.4%
Poor mental health	12.8%
Poor physical health	8.3%
No health insurance	8.8%
Visited doctor (checkup)	74.2%
Visited dentist	71.2%
Cholesterol screening	88.5%
Teeth loss	11.9%

Veterans & disability

Veterans	Count	%
Civilian veterans	39	2.9%

Disability	%
Any disability	11.2%
Under 18	4.5%
18–64 years	9.8%
65 and over	26.1%

Health insurance coverage

Type	%
Private insurance	82.9%
Public insurance	28.8%
Uninsured under 19	1.3%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	1,654	93.9%
Spanish	32	1.9%
Other Indo-European	29	1.8%
Asian & Pacific Islander	0	0.0%
Other languages	3	0.2%

Place of birth & citizenship

Origin	Count	%
Native born (US)	1,697	96.4%
Born in same state	1,695	96.3%
Born in different state	1,360	77.2%
Foreign born	2	0.1%
Naturalized citizen	64	3.6%
Not a US citizen	35	54.7%

Ancestry

Ancestry	Count	%
English	495	28.1%
Italian	119	6.8%
French	90	5.1%
Arab	90	5.1%

Ancestry	Count	%
Polish	52	3%
German	48	2.7%
Dutch	16	0.9%

Technology access

Metric	% of households
Computer access	38.2%
Internet access	93.9%

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

Frequently asked questions

What ZIP codes does Alton, IA have?

Alton, IA has one ZIP code: 51003. Each ZIP code serves a distinct delivery area within the city and surrounding region.