 From its western terminus at SR 20 northwest of Cumming, the route, locally known as Sawnee Drive for this portion, runs west to meet SR 9 just north of downtown Cumming, connecting SR 20 and SR 9 without having to travel through the heart of Cumming.SR 306 and SR 9 are then co-signed on their way northeast toward the community of Coal Mountain, before SR 306 departs SR 9 and travels to the east to its interchange with US 19/SR 400 at exit 17, which is the northernmost interchange of SR 400's controlled access portion.SR 306 continues northeast, now known as Keith Bridge Road, through northern and northeastern Forsyth County to reach its eastern terminus at SR 53, just west of the northern part of Lake Lanier.