 In 1955, MD 309 gained its northern segment by assuming MD 303, which originally followed the Queen Anne–Centreville portion of the present MD 309.When MD 309 moved to a new alignment between Cordova and Queen Anne in the early 1960s, MD 303 was assigned to the old alignment.MD 309 begins at an intersection with US 50 (Ocean Gateway) opposite Airport Road to the east of Easton Airport in Easton.