The passing of the
Chinese Immigration Act 1855 through the
Parliament of Victoria severely limited the number of Chinese passengers permitted on an arriving vessel. To evade the new law, ship's captains landed many Chinese in the south-east of South Australia, from where the new arrivals travelled more than 400 km across country to the Victorian goldfields, along tracks including what is now Pyrenees Highway. Construction of a replacement
Glenmona Bridge as a wrought-iron lattice-girder deck-truss bridge over
Bet Bet Creek at
Bung Bong was completed in 1871, and still stands, minus the deck, today; it replaced a timber structure from 1857 which was washed away by severe floods in 1870. It is the third-oldest of its type in Victoria, is listed on the
Victorian Heritage Register, and stands just to the south of the modern-day bridge used today by the highway. The passing of the
Country Roads Act 1912 through the Parliament of Victoria provided for the establishment of the
Country Roads Board (later
VicRoads) and their ability to declare Main Roads, taking responsibility for the management, construction and care of the state's major roads from local municipalities.
Ararat-(Elmhurst-)Avoca Road from
Ararat through
Elmhurst and
Amphitheatre to
Avoca, and
Avoca-Maryborough Road from Avoca to
Bung Bong, were declared Main Roads on 31 May 1915; and between Joyces Creek through
Newstead to
Castlemaine on 28 June 1915; and the rest of Avoca-Maryborough Road between Bung Bong and Maryborough was declared a Main Road on 21 June 1915. provided for the declaration of State Highways, roads two-thirds financed by the state government through the Country Roads Board.
Pyrenees Highway was declared a State Highway in August 1938, the previous alignment of
Calder Highway between Castlemaine and
Elphinstone was added to the eastern end of Pyrenees Highway. Pyrenees Highway was signed as State Route 122 between Ararat and Elphinstone in 1986; with Victoria's conversion to the newer alphanumeric system in the late 1990s, this was replaced by route B180. The passing of the
Road Management Act 2004 granted the responsibility of overall management and development of Victoria's major arterial roads to
VicRoads: in 2011, VicRoads re-declared the road as Pyrenees Highway (Arterial #6740) between
Western Highway in
Ararat and
Calder Freeway at
Elphinstone; while the road south of Ararat is signed solely as B180, it is not usually referred to as part of Pyrenees Highway. ==Major intersections and towns==