51566 ZIP Code, Red Oak, IA

51566 is a ZIP code in Red Oak, Iowa — mostly in Montgomery County (91% of its land), with smaller parts in Page and Pottawattamie counties. It covers 176 square miles of land. The closest ZIP codes are 51573, 51533 and 51532. 7,010 people live here in 3,128 households. It is rural, with fewer than 100 people per square mile, and owners and renters are mixed (64% own). Median household income is $56,637, below the Iowa median of $75,059.

Quick facts

Key figures

MeasureValue
Residents7,010
Households3,128
Median household income$56,637
Income per person$37,850
Median age42.1
Homeowners63.7%
Median home value$134,200
Median rent$829
Bachelor's degree or higher20.9%
Average commute (minutes)20.4
Households with kids under 1829.4%
Moved in the past year11.1%
Below the poverty line17.2%
Broadband internet84.6%
Speak a non-English language at home3.4%

Household income

% of householdsValue
<$10K5.2%
$10–15K8.2%
$15–25K9.2%
$25–35K9.0%
$35–50K12.3%
$50–75K15.2%
$75–100K13.7%
$100–150K13.3%
$150–200K10.5%
$200K+3.5%

Age

% of all residentsValue
<1012.1%
10–1913.3%
20–245.4%
25–3410.3%
35–4412.1%
45–5413.4%
55–6412.7%
65–7411.1%
75+9.6%

Tenure

% of housing unitsValue
Owned, with mortgage31.8%
Owned outright26.7%
Rented32.8%
Vacant8.8%

Type of building

% of housing unitsValue
Detached house80.6%
Townhome0.3%
2–4 units9.1%
5–19 units3.7%
20+ units3.4%
Mobile / other3.1%

Businesses in 51566

207 business establishments with 2,900 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

51566 has 8 USPS carrier routes with 3,113 residential and 212 business mailboxes. Open the EDDM route map.

Carrier routes in 51566

51566 has 8 USPS carrier routes (4 city (C), 4 rural (R)) with 3,113 residential and 212 business mailboxes. Routes range from 38 homes (R005) to 650 homes (R004); the median route has 460 homes. The Census counted 3,128 households in 51566 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2491
250–4996
500–7491
750–9990
1,000–1,4990
1,500+0

Best routes in 51566 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

  1. Route C003 — USPS business mailboxes 58, 498 homes
  2. Route R004 — USPS business mailboxes 46, 650 homes
  3. Route C005 — USPS business mailboxes 37, 478 homes
  4. Route R002 — USPS business mailboxes 31, 262 homes
  5. Route C002 — USPS business mailboxes 24, 471 homes

Select these 5 routes on the route map

Every carrier route in 51566

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
C001City4486$79,749———
C002City47124$50,883———
C003City49858$52,782———
C005City47837$52,782———
R002Rural26231$83,696———
R003Rural2688$109,106———
R004Rural65046$57,405———
R005Rural382$83,696———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 51566 on the EDDM route map.

How route demographics are estimated

Mailbox counts come from USPS; demographics are estimates

The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).

How a route gets its figures: the block-group length-share method

We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.

Margins of error

Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.

Different years

USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.

Why some routes show identical figures

Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.

Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Nearby ZIP codes

Areas that include 51566

Mail every home in 51566

Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.

EDDM guides

ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 51566, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 51566 in?
51566 is a Red Oak, IA mailing address. By land area, 2% lies inside Red Oak; the rest is outside any Census-defined city or community.
What county is 51566 in?
51566 is mostly in Montgomery County (91% of its land), with smaller parts in Page and Pottawattamie counties.
What is the population of 51566?
About 7,010 people (±229), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 6,772.
What is the median household income in 51566?
$56,637 (±$11,260), compared with $75,059 for Iowa as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 51566?
8 USPS carrier routes with 3,113 residential and 212 business mailboxes (3,325 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 51566?
The closest, measured center to center: 51573 (7.5 mi, Stanton), 51533 (7.9 mi, Emerson), 51532 (10.6 mi, Elliott), 51638 (12.4 mi, Essex), 51541 (12.9 mi, Henderson) and 50864 (13.5 mi, Villisca).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.