Australia’s east-coast wall is a watershed, not one ridge
The Great Dividing Range—East Australian Cordillera—runs more than 3,500 kilometres from Torres Strait’s Dauan Island down the east coast and west across Victoria into the Wimmera. It is the world’s fifth-longest land-based mountain chain, yet it is a cordillera of plateaus and scarps, not a single crest.
The real crest is a watershed: rivers to the east drain to the Pacific, the Tasman Sea, or Bass Strait, while those to the west feed inland systems such as the Murray–Darling. Collisions in the Carboniferous, more than 300 million years ago, raised the highlands, which have been heavily eroded since. All of mainland Australia’s alpine country belongs to the range, including Mount Kosciuszko at 2,228 metres in the Main Range and the Australian Alps of southern New South Wales and eastern Victoria.
The steep rise from coast to upland wrings rain from moist air and has carved deep gorges; rivers plunging off the eastern escarpment create many waterfalls. In winter the range shields Sydney, the Hunter Valley, Canberra, and the Monaro from icy south-westerly fronts, while exposed crest towns such as Oberon get rain from every direction. The ski resorts of Thredbo, Perisher, and Charlotte Pass sit in the high country.
For tens of thousands of years Aboriginal peoples lived in the ranges, leaving decorated caves, campsites, and trails linking coast and interior. After 1788 the Blue Mountains stalled Sydney’s settlers, partly because they followed creeks instead of ridges, until Blaxland, Lawson, and Wentworth crossed along the ridgelines in 1813. Cunningham, Oxley, Hume, Strzelecki, Leichhardt, and Mitchell followed in search of farmland, and by the late 1830s Gippsland, the Riverina, the Liverpool Plains, and the Darling Downs had been taken from their owners.
Spurs such as the Blue Mountains, Barrington Tops, and the Bunya Mountains branch off the core, crossed by passes including Cunninghams Gap and Dead Horse Gap. Flatter, well-watered tablelands like the Atherton Tableland became farmland, and Canberra and Toowoomba stand on the uplands. Many areas remain remote: in eastern Victoria only the Great Alpine Road crosses the highlands north to south.
Source: Great Dividing Range
