The portion of the present-day route west of PA 465 in Mooredale became part of US 11 and PA 13 in 1926, with the latter designation removed two years later. PA 174 was designated in 1928 between Boiling Springs and PA 641 west of Mechanicsburg. In 1937, the route was extended west from Boiling Springs to US 11 in Mooredale. US 11 and PA 33 switched alignments between Shippensburg and Carlisle in 1941, with PA 33 designated onto the present-day route west of Mooredale. In the 1960s, PA 33 was decommissioned and PA 174 was extended west to US 11/PA 533 in Shippensburg.