Jackson County in Florida covers approximately 917 square miles.
Eastern Loudoun County is now a part of the Washington, DC metro area and has many high tech firms along with many retail vendors. The western part of the county is rural and has farms and is very rustic and scenic. Dulles Airport is located in eastern Loudoun County.
Onondaga County, NY is 806 square miles.
Marquette County, Michigan is 3,425 square miles.
Darlington County, SC is 567 square miles.
Hennepin County, Minnesota is 606 square miles.
The smallest county in Texas is Rockwall County, which is about 147 square miles in size.
There are 2,569 square miles in Lincoln County, Nevada.
Tillamook County, Oregon is 1,133 square miles.
Fulton County, GA's area is 534.75 square miles.
Baldwin County, AL's area is 2,027 square miles.
Loudoun County, Virginia has a land area of approximately 520 square miles.