Loudon County is just northwest of Fairfax County and is bordered along the northern edge by the Potomac River. The eastern portion of the county is heavily developed and is a major 'bedroom community' for those who work in Fairfax and DC. The large western portion of Loudon retains much of it's rural flavor, although it, too, continues to experience a smaller rate of development.http://www.bigvirginia.com/loudon-county/