Due to extensive changes in designations in both states during the 20th century, the entire length of the present highway consists of renamed segments from other highways. The New York portion of the cross-state Route 74 west of Ticonderoga was designated as part of NY 73 in the 1930 renumbering of state highways in New York, while the Vermont section carried several different designations from the 1920s to the late 1930s, when it became solely part of Vermont Route F-9. NY 73 was extended east to Lake Champlain in the 1950s—replacing New York State Route 347—and VT F-9 was split into VT 73 and VT 74 shortly afterward. The Schroon–Ticonderoga highway was redesignated as NY 74 on July 1, 1972 after NY 73 was cut back to its current eastern terminus in Elizabethtown.