Polk County is located in the central portion of the U.S. state of Florida. The county population was 725,046, as of the 2020 census. Its county seat is Bartow, and its largest city is Lakeland. Polk County comprises the Lakeland–Winter Haven Metropolitan Statistical Area. This MSA is the 81st-most populous metropolitan statistical area and the 89th-most populous primary statistical area of the United States as of July 1, 2012. The center of population of Florida is located in Polk County, near the city of Lake Wales. Polk County is home to one public university, one state college, and four private universities. History Early history The first people to inhabit the area now called Polk County were the Paleoindians who arrived in Florida at least 12,000 years ago, late in the last ice age. With large amounts of water locked up in continental ice caps, the sea level was more than lower than at present. The Florida peninsula was twice as wide as it is today, and Florida was cooler and much drier, with few, if any, flowing rivers. Both animals and humans were dependent on scattered water holes, such as sinkholes, deep holes in otherwise dry river beds, and rain-fed lakes perched on impervious clay. Most Paleoindian campsites found in Florida have been found at water holes. The largest collection of late (more than 9,500 years ago) Paleoindian microlithic tools known from Florida were found in Lake Weohyakapka, near Nalcrest in Polk County. As sea levels rose and Florida became warmer and wetter, the Paleoindian period was followed by the Archaic period. The Archaic period ended 2,500 to 3,000 years ago, with the emergence of recognizable archaeological cultures in Florida. In eastern Polk County, the Kissimmee River valley was occupied by people of the Belle Glade culture, which persisted from about 3,000 years ago until the collapse of the Native American population in Florida after 1700. Native American people in western Polk County were part of, or influenced by, the Manasota culture, which flourished from 2,500 years ago until c. 800, when it was replaced by the Safety Harbor culture, from c. 800 until after 1700. The Peace River valley may have hosted a distinct culture during the Safety Harbor period. In 1539, Ponce De Leon sent a detachment (between 80 and 180 men) of his expedition from his landing place on Tampa Bay across northern Polk County to visit