Maricopa County, AZ
Maricopa County is located in south-central Arizona and encompasses an area of 9,224 mi². Within its boundaries lies five Indian reservations. It is the most populous county in the state, with 4,410,824 residents as of 2018. The county seat is located in Phoenix, which is also the state capital. Established February 14, 1781, the county was named after the Maricopa Indians.