Ada County, Idaho facts for kids

Quick facts for kids Ada County
U.S. county
James A. McClure Federal Building and U.S. Courthouse in Boise, Idaho.
Seal
Location within the U.S. state of Idaho
Idaho's location within the U.S.
Country	United States
State	Idaho
Founded	December 22, 1864
Named for	Ada Riggs
Seat	Boise
Largest city	Boise
Area
• Total	1,060 sq mi (2,700 km2)
• Land	1,053 sq mi (2,730 km2)
• Water	7.9 sq mi (20 km2)  0.7%
Population  (2020)
• Total	494,967
• Estimate  (2022)	518,907
• Density	467.0/sq mi (180.3/km2)
Time zone	UTC−7 (Mountain)
• Summer (DST)	UTC−6 (MDT)
Congressional districts	1st, 2nd
County Code: 1A

Ada County is located in the southwestern part of Idaho, United States. As of the 2020 census, the county had a population of 494,967, which by 2022 was estimated to have risen to 518,907. Ada County is by far the state's most populous county; it is home to 26.8% of the state's population. The county seat and largest city is Boise, which is also the state capital. Ada County is included in the Boise metropolitan area. The Ada County Highway District has jurisdiction over all the local county and city streets, except for private roads and state roads. In the interior Pacific Northwest east of the Cascade Range, Ada County ranks second in population, behind Spokane County, Washington.

History

Ada County was created by the Idaho Territory legislature on December 22, 1864, partitioned from Boise County. It is named for Ada Riggs, the daughter of H. C. Riggs, a member of the legislature; he established the county and was 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 United States 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

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

National protected areas

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

Demographics

2010 census

As of the 2010 census, there were 392,365 people, 148,445 households, and 99,282 families 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.

Education

Public School districts

School districts include:

• Boise School District
• Kuna Joint School District 3
• Melba Joint School District 136
• West Ada School District (Meridian Joint School District 2)

Residents are in the area (and the taxation zone) for College of Western Idaho.

Communities

Cities

Census-designated places

• Avimor
• Hidden Springs

Unincorporated communities

Population ranking

The population ranking of the following table is based on the 2020 census of Ada County.

† county seat

See also

In Spanish: Condado de Ada para niños