There are two counties in the United States known as Hillsborough. Hillsborough County, Florida covers a total area of 1,266.22 square miles (3,279 square kilometers); and Hillsborough County, New Hampshire covers a total area of 892 square miles (2,310 square kilometers).
The largest County in Maine is Aroostook, measuring 6,829 square miles.
Putnam County, Florida has a total area of 827 square miles.
Approx 20105 square miles.
Idaho County is 8,502 sq miles (22,020 km²).
Harney County, OR is 10,226 sq miles (26,485 km²).
Jackson county is 100.6 square miles
Marquette County, Michigan is 3,425 square miles.
Onondaga County, NY is 806 square miles.
Darlington County, SC is 567 square miles.
Tillamook County, Oregon is 1,133 square miles.
Rockwall County: 129 square miles.
Lincoln County is 4 831 square miles.
Hennepin County, Minnesota is 606 square miles.
Fulton County, GA's area is 534.75 square miles.
Baldwin County, AL's area is 2,027 square miles.
Loudon County, TN: 247 square miles.Loudon County, VA: 521 square miles.
Fayette County, Tennessee is 706 square miles.