The areas that were closely settled mostly depended on the climate and soil. At one extreme western Tasmania is too cold and wet, with the soils in the valleys being infertile glacial silt. Thus all attempts to settle and farm in the area failed and the few towns that still exist depend on mining or tourism.

At the other extreme is the area between Port Augusta and Lake Eyre in South Australia. During a decade of unusually high rainfall it was settled, farms were established, roads and railways were built. But this was followed by decades of lower rainfall which combined with the rather infertile soil, led to the whole region being abandoned to become an area of dispersed grazing.

The far north of Australia is a similar story. For 150 years attempts have been made to farm there, often with generous government backing by building infrastructure such as dams and roads. But outside a few isolated areas, nothing has worked.

But where conditions were right, the opportunity to settle and intensively farm was quickly grasped. Southern and north-eastern Victoria was first settled by Tasmanians looking for new land once the non mountainous areas of their island with good soil had been settled. Within a few years, vast areas of the fertile, well watered land with volcanic soil had been occupied, initially for grazing, but later for intense farming. But (as a broad generalisation) beyond 100 miles north of Melbourne or west of Sydney the good land degenerates into savannah - prairie which is only good for growing grain and another 100 miles out it further degenerates into semi-arid land only suitable for dispersed grazing.

In summary, the outback was never closely settled because it is incapable of sustaining farming due to a hot, dry climate with infertile soil.