Clayton County is a
county located in the
U.S. state of
Iowa. As of the
2010 census, the population was 18,129.
Its
county seat is
Elkader.
The county was established in 1837 and was named in honor of
John M. Clayton,
United States Senator from
Delaware and later
Secretary of State under President
Zachary Taylor.
Geography

According to the
U.S. Census Bureau, the county has a total area of , of which is land and (1.8%) is water.
It is the fifth-largest county in Iowa by area.
Adjacent counties
*
Allamakee County (north)
*
Crawford County,
Wisconsin (northeast)
*
Grant County,
Wisconsin (east)
*
Dubuque County (southeast)
*
Delaware County (south)
*
Buchanan County (southwest)
*
Fayette County (west)
*
Winneshiek County (northwest)
Major highways
*
U.S. Highway 18
*
20px U.S. Highway 52
*
Iowa Highway 3
*
Iowa Highway 13
*
Iowa Highway 56
*
Iowa Highway 76
*
Iowa Highway 128
National protected areas
*
Driftless Area National Wildlife Refuge (part)
*
Effigy Mounds National Monument (part)
*
Upper Mississippi River National Wildlife and Fish Refuge (part)
Geology
Clayton County is part of the
Driftless Area, a region that completely missed being ice-covered during the last
ice age. Streams have deeply carved valleys, while the
Mississippi River has spectacular bluffs.
Demographics
2010 census
The 2010 census recorded a population of 18,130 in the county, with a population density of . There were 8,999 housing units, of which 7,599 were occupied.
2000 census
As of the
census of 2000, there were 18,678 people, about 7,500 households, and 1 family residing in the county. The
population density was 24 people per square mile (9/km
2). There were 8,620 housing units at an average density of 11 per square mile (4/km
2). The racial makeup of the county was 98.93%
White, 0.14%
Black or
African American, 0.22%
Native American, 0.11%
Asian, 0.01%
Pacific Islander, 0.19% from
other races, and 0.41% from two or more races. 0.76% of the population were
Hispanic or
Latino of any race.
There were 7,375 households, out of which 30.90% had children under the age of 18 living with them, 59.70% were
married couples living together, 6.10% had a female householder with no husband present, and 30.40% were non-families. 26.30% of all households were made up of individuals, and 13.30% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 2.98.
In the county, the population was spread out, with 25.40% under the age of 18, 6.50% from 18 to 24, 26.00% from 25 to 44, 23.60% from 45 to 64, and 18.50% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 97.60 males. For every 100 females age 18 and over, there were 95.50 males.
The median income for a household in the county was $34,068, and the median income for a family was $40,199. Males had a median income of $27,165 versus $19,644 for females. The
per capita income for the county was $16,930. About 5.70% of families and 8.60% of the population were below the
poverty line, including 9.60% of those under age 18 and 9.40% of those age 65 or over.
Communities
Cities
*
Clayton
*
Edgewood
*
Elkader
*
Farmersburg
*
Garber
*
Garnavillo
*
Guttenberg
*
Luana
*
Marquette
*
McGregor
*
Monona
*
North Buena Vista
*
Osterdock
*
Postville
*
St. Olaf
*
Strawberry Point
*
Volga
Unincorporated communities
*
Beulah
*
Ceres
*
Clayton Center
*
Communia
*
Eckards
*
Elkport
*
Fairview
*
Froelich
*
Giard
*
Gunder
*
Hardin
*
Highland
*
Littleport
*
McGregor Heights
*
Mederville
*
Millville
*
Motor
*
Osborne
*
Saint Sebald
*
Thomasville
*
Turkey River
*
Updegraff
*
Watson
*
Wood
Townships
Clayton County is divided into these
townships:
*
Boardman
*
Buena Vista
*
Cass
*
Clayton
*
Cox Creek
*
Elk
*
Farmersburg
*
Garnavillo
*
Giard
*
Grand Meadow
*
Highland
*
Jefferson
*
Lodomillo
*
Mallory
*
Marion
*
Mendon
*
Millville
*
Monona
*
Read
*
Sperry
*
Volga
*
Wagner
Population ranking
The population ranking of the following table is based on the
2010 census of Clayton County.
† ''county seat''
Politics
See also
*
National Register of Historic Places listings in Clayton County, Iowa
*
Clayton County Courthouse
References
External links
*
Clayton County Development Corporation's websiteClayton County Health and Demographic Data
{{authority control
Category:1837 establishments in Wisconsin Territory
Category:Populated places established in 1837
Category:Driftless Area
Category:Iowa counties on the Mississippi River