Ada County, Idaho facts for kids

Kids Encyclopedia Facts
Ada County, Idaho
Seal of Ada County, Idaho
Map
Map of Idaho highlighting Ada County
Location in the state of Idaho
Map of the USA highlighting Idaho
Idaho's location in the U.S.
Statistics
Founded December 22, 1864
Seat Boise
Largest City Boise
Area
 - Total
 - Land
 - Water

1,060 sq mi (2,745 km²)
1,053 sq mi (2,727 km²)
7.9 sq mi (20 km²), 0.7%
PopulationEst.
 - (2015)
 - Density

434,211
373/sq mi (144/km²)
Time zone Mountain: UTC-7/-6
Website: www.adaweb.net
Named for: Ada Riggs, first pioneer child born in county

Ada County is a county in the southwestern part of the U.S. state of Idaho. As of the 2010 Census, the county had a population of 392,365, making it the most populous county in Idaho. The county seat and largest city is Boise, which is also the state capital.

Ada County is included in the Boise, ID Metropolitan Statistical Area.

Ada County is by far the state's largest in population, containing more than one quarter of the state's residents, and contains its only county highway district; the Ada County Highway District (ACHD) has jurisdiction over all the local county and city streets, except for private roads and state roads. In the interior Northwest east of the Cascade Range, Ada County ranks second in population behind only Spokane County, Washington.

History

Ada County was created by the Idaho Territorial Legislature on December 22, 1864, partitioned from Boise County. It is named for Ada Riggs, the first pioneer child born in the area and the daughter of H.C. Riggs, a co-founder of Boise. Canyon County, which originally included Payette County and most of Gem County, was partitioned from western Ada County in 1891.

Geography

According to the U.S. Census Bureau, the county has a total area of 1,060 square miles (2,700 km2), of which 1,053 square miles (2,730 km2) is land and 7.9 square miles (20 km2) (0.7%) is water. The Boise River flows through the northern portion of the county, and the northwest border is bounded by the foothills of the Boise Range mountains, the summits are in adjacent Boise County. The southwestern border of the county is bounded by the Snake River.

Adjacent counties

Major highways

  • I-84.svg - Interstate 84
  • I-184.svg - Interstate 184
  • US 20.svg - US 20
  • US 26.svg - US 26
  • US 30.svg - US 30
  • ID-16.svg - SH-16
  • ID-21.svg - SH-21 - Ponderosa Pine Scenic Byway
  • ID-44.svg - SH-44
  • ID-55.svg - SH-55 - Payette River Scenic Byway
  • ID-69.svg - SH-69

County roads and highways are maintained by the Ada County Highway District (ACHD).

National protected areas

  • Boise National Forest (part)
  • Snake River Birds of Prey National Conservation Area (part)

Demographics

Historical population
Census Pop.
1870 2,675
1880 4,674 74.7%
1890 8,368 79.0%
1900 11,559 38.1%
1910 29,088 151.6%
1920 35,213 21.1%
1930 37,925 7.7%
1940 50,401 32.9%
1950 70,649 40.2%
1960 93,460 32.3%
1970 112,230 20.1%
1980 173,036 54.2%
1990 205,775 18.9%
2000 300,904 46.2%
2010 392,365 30.4%
Est. 2015 434,211 10.7%
U.S. Decennial Census
1790-1960 1900-1990
1990-2000 2010-2013

2000 census

As of the census of 2000, there were 300,904 people, 113,408 households, and 77,344 families residing in the county. The population density was 285/mi² (110/km²). There were 118,516 housing units at an average density of 112/mi² (43/km²). The racial makeup of the county was 92.86% White, 0.65% Black or African American, 0.69% Native American, 1.74% Asian, 0.15% Pacific Islander, 1.67% from other races, and 2.24% from two or more races. Hispanic or Latino of any race were 4.48% of the population.

There were 113,408 households out of which 36.20% had children under the age of 18 living with them, 55.10% were married couples living together, 9.40% had a female householder with no husband present, and 31.80% were non-families. 23.80% of all households were made up of individuals and 6.07% had someone living alone who was 65 years of age or older. The average household size was 2.59 and the average family size was 3.11.

In the county, the population was spread out with 27.30% under the age of 18, 10.30% from 18 to 24, 32.50% from 25 to 44, 20.80% from 45 to 64, and 9.10% who were 65 years of age or older. The median age was 33 years. For every 100 females there were 100.6 males. For every 100 females age 18 and over, there were 98.9 males.

The median income for a household in the county was $46,140, and the median income for a family was $54,416. Males had a median income of $37,867 versus $26,453 for females. The per capita income for the county was $22,519. About 5.40% of families and 7.70% of the population were below the poverty line, including 9.20% of those under age 18 and 5.70% of those age 65 or over.

2010 census

As of the 2010 United States Census, there were 392,365 people, 148,445 households, and 99,282 families residing in the county. The population density was 372.8 inhabitants per square mile (143.9/km2). There were 159,471 housing units at an average density of 151.5 per square mile (58.5/km2). The racial makeup of the county was 90.3% white, 2.4% Asian, 1.1% black or African American, 0.7% American Indian, 0.2% Pacific islander, 2.4% from other races, and 2.8% from two or more races. Those of Hispanic or Latino origin made up 7.1% of the population. In terms of ancestry, 19.4% were German, 15.9% were English, 11.8% were Irish, and 8.6% were American.

Of the 148,445 households, 35.6% had children under the age of 18 living with them, 52.4% were married couples living together, 10.0% had a female householder with no husband present, 33.1% were non-families, and 25.0% of all households were made up of individuals. The average household size was 2.58 and the average family size was 3.11. The median age was 34.8 years.

The median income for a household in the county was $55,835 and the median income for a family was $67,519. Males had a median income of $48,290 versus $34,875 for females. The per capita income for the county was $27,915. About 6.9% of families and 10.2% of the population were below the poverty line, including 11.8% of those under age 18 and 6.8% of those age 65 or over.

Communities

Cities

Census-designated place


Ada County, Idaho Facts for Kids. Kiddle Encyclopedia.