Most of Earth's Continents are known for their major river systems; there is the Amazon Basin of South America, the Mississippi Watershed of North America, the Nile and Congo systems of Africa, the Rhine of Europe and the Ganges-Brahmaputra and Yangtze of Asia, among many others. When it comes to Australia, however, a nation Continent known for its vast desert landscapes and sunny climate, rivers do not immediately come to mind.
The Murray-Darling River System of southeast Australia is the largest on that Continent. The Murray River, which rises on the western slope of the Great Dividing Range in New South Wales and Victoria, is Australia's longest river; flowing westward to form the border between those two States, it then angles to the southwest across the southeastern corner of South Australia, entering the Southern Ocean south of Adelaide to complete its 1476 mile course. The major tributary of the Murray is the Darling River, which merges with the Murray in western New South Wales; the Darling rises as numerous tributaries along the western slope of the Great Dividing Range, from southeastern Queensland through much of New South Wales, and along the southern flank of the Expedition Range, northwest of Brisbane. While the Darling itself is "only" 915 miles long, the area of its watershed is larger than that of the Murray above their junction.
Since the Great Dividing Range lies close to the eastern coast of Australia and since rain-producing weather systems arrive from the east, the Murray-Darling watershed drains the dry-side of those highlands; numerous coastal rivers, rising on the east slope of the Divide discharge far more water to the sea than does the massive Murray-Darling River System. Finally, this system, like the Mississippi-Missouri network of North America, highlights the fact that our longest continuous waterways do not always correspond to the course of our "longest rivers." The latter is determined by how we choose to name the segments of any given watershed; the longest waterway in North America begins at the uppermost headwaters of the Missouri River and ends at the tip of the Mississippi Delta while the longest waterway in the Murray-Darling System begins in the mountains of southeast Queensland and ends at the mouth of the Murray River, on the coast of South Australia.
