ZIP Codes of Lyon County, IA

Population & People
Population & People
Total Population
12,262
Household Income
Household Income
Median Income
$78,932
Housing
Housing
Total Housing Units
4,918
Business & Economy
Business & Economy
Total Businesses
407
Employment
Employment
Employment Rate
66.48%
Education
Education
Bachelor's Degree+
20.06%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 8 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:8 ZIP Codes (7 Standard, 1 PO Box, 0 Unique) [See All]
Area Code:712
Timezone:Central (GMT -06:00)
Local Time:2:11:53 PM
Population:12,262 [See All]
FIPS:19119
Land Area:576 sq mi
Water Area:0 sq mi
Coordinates:43.3779, -96.2283
Quick Link:
https://www.zip-codes.com/county/ia-lyon.asp
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Iowa's #62 most populous county
12,262 residents across 8 ZIPs — #62 of 99 Iowa counties.

Standout ZIPs in this County


Most Populous
Rock Rapids · 4,041 people
33.0% of county total
Highest Income
Lester · $95,625 median
1.2× county average
Largest Land Area
Rock Rapids · 150.2 sq mi
Spans the most ground
Fastest Growth
Larchwood · 18.7% (10-yr)
1,771 → 2,103 residents
Most Educated
Larchwood · 25.1% bachelor's+
331 of 1,319 adults 25+

Things worth knowing about Lyon County


12,262 residents live across 8 ZIPs covering 576 sq mi, served by 8 distinct USPS-recognized cities.

Population moved from 11,494 to 12,262 from 2014 to 2024 — a +6.7% change. 4 ZIPs gained residents, 4 lost.

The county's wealthiest ZIP 51242 (Lester, $95,625 median) and poorest ZIP 51237 (George, $61,667) are 17.9 miles apart — a 1.6× income gap across local geography.

Median home values vary 3.0× across this county — from $92,200 in 51243 (Little Rock) to $280,600 in 51241 (Larchwood).

Density varies across the county — from 13 people/sq mi in 51243 (Little Rock) to 104 in 51242 (Lester).

Educational attainment ranges from 7.6% bachelor's+ in 51235 (Doon) to 25.1% in 51241 (Larchwood) — the breadth of educational profiles across the area.

Within Iowa, this is the #62 most populous of 99 counties and ranks #30 for median household income with the #6 fastest decade growth .

Weighted by population, the typical household earns about $76,785 across the county — reflecting what a typical resident sees, not a simple ZIP average.

20.1% of adults age 25+ hold a bachelor's degree or higher (1,572 of 7,838 reporting).

7 Standard delivery, 1 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Lyon County


Big & sparse

A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.

Total area
576
square miles
Avg density
21.3
people per sq mi
Population
12,262
across 8 ZIPs
Rock Rapids
150.2 sq mi
4,041 residents
Inwood
104.5 sq mi
1,914 residents
George
93.0 sq mi
1,605 residents

All ZIP Codes in Lyon County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
51246Rock RapidsStandard4,041$72,400150.27.7%
51241LarchwoodStandard2,103$87,44690.618.7%
51240InwoodStandard1,914$83,929104.59.1%
51237GeorgeStandard1,605$61,66793.0-1.8%
51235DoonStandard1,007$71,01645.3-3.0%
51243Little RockStandard735$83,75055.7-10.9%
51230AlvordStandard478$75,62532.9-6.6%
51242LesterPO Box379$95,6253.684.0%

Adjacent & Nearby Counties