Williamson county is one of the highest income per capita and most influential in Tennessee.  Williamson county houses 5 main cities witin its boarders mainly Brentwood, Franklin, Thomson Station, Fairview,  and Nolensville Tn.  Within this area there are several zip codes those being 37046, 37135, 38476, 37062, 37064, 37067, 37069, 37174 and 37179.  It is always a pleasure to wash in Williamson county.