 These turnpikes were reconstructed as state roads in the 1910s north of Frederick and in the early 1920s from Frederick south to Tuscarora.When US 15 was assigned in 1927, the Tuscarora – Point of Rocks highway had yet to be improved; this section was paved in the early 1930s.The modern Point of Rocks Bridge was built in the late 1930s after its predecessor was destroyed in a flood.