SR 18 begins in extreme southeastern Fayette County in West Tennessee at the northern terminus of Mississippi Highway 7, approximately 1.2 miles north of Michigan City, Mississippi as a rural two lane route.
State Route 18 begins in a rural part of southeastern Fayette County, Tennessee, at the intersection with Mississippi Highway 7, roughly 1.2 miles north of the town of Michigan City, Mississippi, functioning as a two-lane road.