 It overlaps Route 181, heading east, to cross the West Branch Farmington River, then continues east over the Saville Dam past Lake McDonough, ending at a "Y" intersection with Route 219.The section of Route 318 from Route 181 to Route 219 is designated a scenic road.Route 318 was commissioned from SR 860 (Ripley Hill Road) and SR 418 (Saville Dam Road) in 1963 and has had no significant changes since.