Gondwanaland Separates
50 million years B.P. the 'supercontinent' of Gondwanaland began to break up and move northwards. Australia separated from the land mass. The south eastern highlands were lifted which in turn caused the Murray Darling basin to subside. Rising sea levels of 20 million years ago resulted in the covering of this basin by the Murravian Gulf. The ancient Darling River flowed into this gulf somewhere north of today's Menindee. The climate was much wetter and more humid, vegetation consisted of rainforests and lakes and wetlands were abundant. Aquatic creatures such as cockles, oysters, sea urchins and starfish thrived in the warm shallow waters

The Sea Retreats
12 million years B.P. the sea retreated due to the combined affects of uplifting land and lowering sea levels

Formation of River Murray
6 million years later the sea once again inundated the western section of the Murray Darling basin. After several advances and retreats, between 4 and 2 million years ago, the sea finally retreated to the south west. The ancient Murray River cut its channel, reaching the sea near present day Kangaroo Island.

Tectonic Upheaval
Approximately 2 million B.P., uplifting of tectonic plates in the present day Swan Reach area dammed the Murray River, preventing the waters from reaching the sea. The body of fresh water which formed behind this uplift, Lake Bungunnia, reached back as far as the junction of the Murrumbidgee and Murray Rivers and covered an area of 33,000 square kilometres. The ancient Darling River flowed from the north into this lake which contained abundant fish, invertebrates and tortoises. Plants and animals flourished around the shoreline.

Time of Plenty and the Arrival of the Aboriginals
Between 55,000 and 30,000 years B.P., the river, lakes and wetlands were full and their surrounding environments were going through a time of plenty. Megafauna such as the giant kangaroo Procoptodon goliah, and the immense flightless bird Genyornis newtoni grazed on the vast open grasslands and the hippo like Zygomaturus trilobus fed on water plants within the lakes and wetlands. It was during this time of plenty that the Negrito Aboriginal people are believed to have arrived in the Darling River area. They would have enjoyed abundant and easily obtainable food and water resources.

Warmer Climate
Between 16,000 and 13,000 years ago the climate slowly warmed, the glaciers of the Snowy Mountains melted and the rivers decreased in size and flow rates. The changing climate saw the return of trees to the grasslands of the western region. The climate and vegetation patterns we see today appeared approximately 10,000 years ago.

European Settlement
The first European to possibly sight the Greater Darling Anabranch was Captain Charles Sturt during his boat trip down the Murrumbidgee and Murray rivers during 1829 and 1830. One morning Sturt and his party were confronted by a hostile group of around 600 people on a large sand spit. Only after the tensions had subsided did Sturt notice that the sand spit marked the entrance to a large river, the Darling. Writing of the entrance to the Darling, Sturt commented," The river preserved a breadth of one hundred yards and a depth of greater than twelve feet. Its banks were sloping and grassy, and were overhung by trees of magnificent size. Its waters, though sweet, were turbid and had a taste of vegetable decay". Sturt travelled on down the Murray, past the entrance of the Anabranch on the northern shore. No mention was made in his journals of any sighting.

Tona Today
Mr Russell Elliot purchased Tona Station in 2002. Tona currently covers approximately 2,000 Ha (5,000ac) of which one third is wetlands and floodways, one third alluvial shrub lands and one third ridge lands and dune fields. It has a 30km frontage on the Great Darling Anabranch. Like many landscapes of the area, one hundred and fifty years of excessive stock grazing, cereal cropping and pest species invasion has severely degraded the landscape, its natural assets and its ecological functions. With the cessation of cropping and grazing, Mr. Elliot hopes to arrest the degradation and embark on a program of reparation.

In comparison to Aborigine history (more than 45,000 years) the presence of white man on this landscape is short. From early European occupation the land was utilised extensively for sheep grazing. Later tree clearing occurred for the production of cereal crops. This dramatic land use change commenced the processes of 'boom and bust.' The variability and unpredictability of Australian weather and dependent export markets has seen the making and breaking of many settlers. To this day the same land uses are in operation - mostly unsustainable in terms of regional economic, environmental and social well being. There is however a growing awareness and commitment for change towards more sustainable industries and lifestyles.

The Anabranch Wetlands of Today
The Anabranch of today receives water from both the Darling to the north and the Murray from the south. The Darling catchment receives the majority of its rain during the summer monsoonal season in Queensland while the Murray River relies on winter and spring rains in the Snowy Mountains and Southern Highlands. Due to river regulation, diversion and abstraction, the natural flow and flooding regime of these rivers have changed dramatically. Prior to river regulation, the Anabranch was a chain of natural ephemeral wetlands that would receive flows when the Darling River flooded. In its upper reaches it would flow 2 out of 3 years during the summer months, and the lower anabranch would receive flood waters from the swollen Murray during the spring floods. Flows in the Darling over recent years have been less than 31 % of natural river flows. These factors have resulted in the lower Anabranch wetlands remaining dry since 1974.