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County ZIP codes · Iowa · FIPS 19141

O'Brien County, IA ZIP Codes

O'Brien County, Iowa has 14 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 8 of the residential ones lie mainly in O'Brien County and 6 mainly in a neighboring county; 11 cross the county line. Median household income ranges from $63,036 in 51058 (Sutherland) to $84,125 in 51046 (Paullina) (Census Bureau, ACS 2020-2024).

  • ACS2020-24
  • Census2020

Where are the ZIP codes of O'Brien County?

51009 · Calumet: $59k51022 · Granville: $97k51029 · Larrabee: $86k51046 · Paullina: $84k51047 · Peterson: $101k51058 · Sutherland: $63k51201 · Sheldon: $69k51231 · Archer: $108k51232 · Ashton: $83k51238 · Hospers: $74k51245 · Primghar: $70k51248 · Sanborn: $64k51346 · Hartley: $72k51350 · Melvin: $77k5134651201510465104751245510585102251248512325135051238510295123151009 · Calumet: $59k51022 · Granville: $97k51029 · Larrabee: $86k51046 · Paullina: $84k51047 · Peterson: $101k51058 · Sutherland: $63k51201 · Sheldon: $69k51231 · Archer: $108k51232 · Ashton: $83k51238 · Hospers: $74k51245 · Primghar: $70k51248 · Sanborn: $64k51346 · Hartley: $72k51350 · Melvin: $77k5134651201510465104751245510585102251248512325135051238510295123151009 · Calumet: $59k51022 · Granville: $97k51029 · Larrabee: $86k51046 · Paullina: $84k51047 · Peterson: $101k51058 · Sutherland: $63k51201 · Sheldon: $69k51231 · Archer: $108k51232 · Ashton: $83k51238 · Hospers: $74k51245 · Primghar: $70k51248 · Sanborn: $64k51346 · Hartley: $72k51350 · Melvin: $77k513465120151046510475124551058510225124851232513505123851029
The residential ZIP codes of O'Brien 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 $64,375 and $72,426.

They carry 14 postal town names.

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

All 14 residential ZIP codes in O'Brien County

8 ZIP codes lie mainly in O'Brien County; 6 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in O'Brien County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
51346 Hartley 2,247 15 $72k $157k 71%
51248 Sanborn 1,534 19 $64k $173k 90%
51245 Primghar 1,377 18 $70k $150k 100%
51046 Paullina 1,326 14 $84k $160k 95%
51058 Sutherland 1,096 13 $63k $133k 93%
51022 Granville 960 13 $97k $175k 58%
51231 Archer 562 23 $108k $190k 100%
51009 Calumet 113 425 $59k $83k 100%

Partly in O'Brien County

Residential ZIP codes mainly in another county that reach at least 1% into O'Brien County, by their share here
In this county
51201 Sheldon 6,430 56 $69k $198k 49%
51238 Hospers 1,502 31 $74k $183k 32%
51029 Larrabee 261 10 $86k – 15%
51350 Melvin 383 9 $77k $79k 7%
51047 Peterson 693 9 $101k $130k 5%
51232 Ashton 658 11 $83k $108k 2%

Download the 14 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?

11 ZIP codes of O'Brien County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in O'Brien County and in the neighboring counties
ZIPIn O'BrienElsewhere
5120149%Sioux County 49%; Lyon County 2%
5134671%Osceola County 20%; Clay County 8%
5124890%Osceola County 10%
5123832%Sioux County 68%
5104695%Cherokee County 5%
5105893%Cherokee County 6%; Clay County 1%
5102258%Sioux County 40%; Plymouth County 3%
510475%Clay County 55%; Buena Vista County 27%; Cherokee County 13%
512322%Osceola County 73%; Lyon County 26%
513507%Osceola County 93%
5102915%Cherokee County 85%

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

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

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. O'Brien County's ZIP codes use 3 prefixes: 510, 512 and 513.

Three-digit prefixes of O'Brien 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 O'Brien County's
PrefixSectional centerHereAll codes
510 Sioux Falls, SD (SCF 570) 6 55
512 Sioux Falls, SD (SCF 570) 6 20
513 Sioux Falls, SD (SCF 570) 2 23

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