Maricopa County is a county in Arizona. It covers 9,225 square miles (5,903,910 acres), which represents less than one percent of the state total. Of the 15 counties in Arizona, Maricopa County is the biggest county in the state (4.2 million people live here, according to 2015 Census estimates). Recent data from Lands of America calculates the average value of ranches, land, farms and other recreational acreage for sale in Maricopa County at $198 per acre. The average list price of property and land for sale was $1,136,391 (the most expensive listing being for $9.7 million) and the median land-parcel size was six acres. Land for sale in Maricopa County totaled 201,346 acres and $39.8 million in overall land value, with the city of Mobile featuring the most land for sale in the county. Farmland was the most common type of land for sale in Maricopa County.