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County ZIP codes · Iowa · FIPS 19119

Lyon County, IA ZIP Codes

Lyon County, Iowa has 12 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 8 of the residential ones lie mainly in Lyon County and 4 mainly in a neighboring county; 7 cross the county line. Median household income ranges from $61,667 in 51237 (George) to $87,446 in 51241 (Larchwood) (Census Bureau, ACS 2020-2024).

  • ACS2020-24
  • Census2020

Where are the ZIP codes of Lyon County?

51201 · Sheldon: $69k51230 · Alvord: $76k51232 · Ashton: $83k51235 · Doon: $71k51237 · George: $62k51239 · Hull: $78k51240 · Inwood: $84k51241 · Larchwood: $87k51242 · Lester: $96k51243 · Little Rock: $84k51246 · Rock Rapids: $72k51247 · Rock Valley: $78k51246512475120151240512375124151239512325123551243512305124251201 · Sheldon: $69k51230 · Alvord: $76k51232 · Ashton: $83k51235 · Doon: $71k51237 · George: $62k51239 · Hull: $78k51240 · Inwood: $84k51241 · Larchwood: $87k51242 · Lester: $96k51243 · Little Rock: $84k51246 · Rock Rapids: $72k51247 · Rock Valley: $78k512465124751201512405123751241512395123251235512435123051201 · Sheldon: $69k51230 · Alvord: $76k51232 · Ashton: $83k51235 · Doon: $71k51237 · George: $62k51239 · Hull: $78k51240 · Inwood: $84k51241 · Larchwood: $87k51242 · Lester: $96k51243 · Little Rock: $84k51246 · Rock Rapids: $72k51247 · Rock Valley: $78k51246512475120151240512375124151239512325123551243
The residential ZIP codes of Lyon County (whole outlines, including the parts in neighboring counties), shaded by median household income in national fifths (ACS 2020-2024). <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $68,799 and $78,358.

They carry 12 postal town names.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 12 residential ZIP codes in Lyon County

8 ZIP codes lie mainly in Lyon County; 4 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Lyon County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
51246 Rock Rapids 4,041 25 $72k $248k 100%
51241 Larchwood 2,103 23 $87k $281k 100%
51240 Inwood 1,914 19 $84k $233k 85%
51237 George 1,605 17 $62k $160k 100%
51235 Doon 1,007 19 $71k $241k 97%
51243 Little Rock 735 14 $84k $92k 86%
51230 Alvord 478 20 $76k $191k 100%
51242 Lester 379 70 $96k $191k 100%

Partly in Lyon County

Residential ZIP codes mainly in another county that reach at least 1% into Lyon County, by their share here
In this county
51232 Ashton 658 11 $83k $108k 26%
51239 Hull 2,876 43 $78k $237k 7%
51247 Rock Valley 5,094 45 $78k $263k 5%
51201 Sheldon 6,430 56 $69k $198k 2%

Download the 12 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

7 ZIP codes of Lyon County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Lyon County and in the neighboring counties
ZIPIn LyonElsewhere
512012%Sioux County 49%; O'Brien County 49%
512475%Sioux County 95%
512397%Sioux County 93%
5124085%Sioux County 15%
5123597%Sioux County 3%
5124386%Osceola County 14%
5123226%Osceola County 73%; O'Brien County 2%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

Which first three digits do Lyon County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Every ZIP code of Lyon County starts with 512.

Three-digit prefixes of Lyon County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Lyon County's
PrefixSectional centerHereAll codes
512 Sioux Falls, SD (SCF 570) 12 20

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.