The present course of MD 135 consists of the original course of the state highway and its extensions westward, and assumption of a portion of MD 38 and all of MD 41. MD 135 also followed a segment of what is today MD 495. The original segment of MD 135 was under construction between McCoole and Westernport in 1930 and completed by 1931. The state highway was constructed between Bloomington and Luke in 1936 and 1937, including the bridge over the Savage River. This segment was connected to Westernport in 1940 by carving a roadbed out of the cliffs of Franklin Hill. MD 38 was paved from its original northern terminus to Altamont between 1924 and 1926 and to the top of Backbone Mountain by 1930. The present segment of MD 38 south to Kitzmiller was under construction by 1930 and completed by 1933. MD 41 included the first section of what is now MD 135 to be constructed; the segment of the state highway between Oakland and Mountain Lake Park was paved between 1916 and 1919. The state highway was extended past Loch Lynn Heights in 1933 and to MD 38 in Deer Park by 1938.