Maricopa County is in the south-central part of the U.S. state of Arizona. As of the 2020 census the population was 4,420,568, or about 62% of the state's total, making it the fourth-most populous county in the United States and the most populous county in Arizona, and making Arizona one of the nation's most centralized states. The county seat is Phoenix, the state capital and fifth-most populous city in the United States.
Maricopa County is the central county of the Phoenix–Mesa–Chandler Metropolitan Statistical Area. The Office of Management and Budget renamed the metropolitan area in September 2018. Previously, it was the Phoenix–Mesa–Glendale metropolitan area, and in 2000, that was changed to Phoenix–Mesa–Scottsdale.
Maricopa County was named after the Maricopa Native Americans. Five Native American Reservations are located in the county. The largest are the Salt River Pima-Maricopa Indian Community (east of Scottsdale) and the Gila River Indian Community (south of Chandler).
Geography
According to the United States Census Bureau, the county has a total area of , of which (0.3%) is covered by water. Maricopa County is one of the largest counties in the United States by area, with a land area greater than that of four other US states. From west to east, it stretches , and from north to south. It is by far Arizona's most populous county, encompassing well over half of the state's residents. It is the largest county in the United States to have a capital city.
Adjacent counties
La Paz County – west
Yuma County – west
Pima County – south
Pinal County – southeast and south
Gila County – east
Yavapai County – north
National protected areas
Sonoran Desert National Monument (part) Tonto National Forest (part)
Regional parks
Maricopa County has 14 regional parks: Adobe Mountain Desert Park Chaparral Lake Estrella Mountain Regional Park Hassayampa River Preserve Indian Mesa Lake Pleasant Regional Park Litchfield Park, Arizona Manistee Ranch McCormick-Stillman Railroad Park Papago Park Phoenix Mountains Preserve Sahuaro Ranch San Tan Mountain Regional Park White Tank Mountain Regional Park.
It also has at least 21 protected areas: Big Horn Mountains Wilderness Daisy Mountain Preserve Deer Valley Petroglyph Preserve Eagletail Mountains Wilderness Harquahala Mountains Hells Canyon Wilderness (Arizona) Hummingbird Springs Wilderness Mesa Grande Mummy Mountain (Arizona) National Memorial Cemetery of Arizona Painted Rock Petroglyph Site Sierra Estrella Signal Mountain Wilderness Sonoran Desert National Monument St. Francis Catholic Cemetery Superstition Mountains Table Top Mountain (Arizona) Tonto National Forest Wabayuma Peak White Tank Mountain Regional Park Woolsey Peak
Flora and fauna
From 2009 to 2011, an inventory of all vascular plants growing along the Salt River (Arizona), Gila River, New River and Agua Fria River and their tributaries in the Phoenix metropolitan area was done. In October 2022, Maricopa County Environmental Services Department detected Dengue virus in mosquitoes they had trapped; in November the first locally transmitted case of dengue fever was reported in the County and Arizona state as a whole - previous dengue cases in Maricopa County had been related to travel.
Demographics
Racial and ethnic composition since 1960
2000 census
As of the census of 2000, 3,072,149 people, 1,132,886 households, and 763,565 families were living in the county. The population density was . The 1,250,231 housing units averaged of . The racial makeup of the county was 77.4% White, 3.7% African American, 1.9% Native American, 2.2% Asian, 12.0% from other races, and 2.9% from two or more races. About 29.5% of the population were Hispanics or Latinos of any race. About 19.1% reported speaking Spanish at home.
Of the 1,132,886 households, 33.0% had children under 18 living with them, 51.6% were married couples living together, 10.7% had a female householder with no husband present, and 32.6% were not families. About 24.5% of all households were made up of individuals, and 7.9% had someone living alone who was 65 or older. The average household size was 2.67, and the average family size was 3.21.
The age distribution in the county was 27.0% under 18, 10.2% from 18 to 24, 31.4% from 25 to 44, 19.8% from 45 to 64, and 11.7% who were 65 or older. The median age was 33 years. For every 100 females, there were 100.10 males. For every 100 females age 18 and over, there were 98.10 males.