Pinal is one of the 15 counties in the state of Arizona. It was created in 1875 from parts of Maricopa and Pima counties. As of the 2010 census the population was 387,365, more than double the 2000 figure of 179,727. The county seat is Florence and the largest city is Casa Grande.
The county has a total area of 5,374 square miles (13,920 km2), of which 5,366 square miles (13,900 km2) is land. Pinal is bordered on the north by Gila, east by Graham, south by Pima and on the west and northwest by Maricopa counties.
The county is served by Interstates 8 and 10.