Maricopa County is the most populous and fastest-growing county in Arizona, with more than four and a half million people living in it. It is the largest of Arizona's fifteen counties and the fourth largest county in the United States, covering 9,224 square miles. This metropolitan area is the main center of political and economic activity in the state, and includes the cities of Phoenix, Mesa, Glendale, Scottsdale, Tempe, Chandler, Peoria and the City of Gilbert. Maricopa County is composed of 53% federal land, 29% private land, 13% state land and nearly 5% tribal land.
It was named after the Maricopa or Piipaash Native American tribe. Phoenix is the seat of Maricopa County, the state capital and the largest city in the state. The county also boasts one of the largest park systems in the U. S.
Department of State, with more than 120,000 acres of open space. Address: 550 West Jackson, Phoenix, Arizona 85003, United States.