 MD 309 is a C-shaped highway that passes through northeastern Talbot County and southeastern Queen Anne's County, connecting Easton and Centreville with Queen Anne, where the highway intersects MD 404.MD 309 was originally designated along the highway between Easton and Queen Anne.The highway was constructed south from Queen Anne to Cordova in the late 1920s along MD 303's current course and from Cordova to Easton in the early 1930s.