It's unnerving to be told that the ground you're standing on isn't real. Such is the case with Australia's Murray River, which according to the Ngarrindjeri people of South Australia is the creation of the spirit Ngurunderi. But although the creation of the river may be shrouded in myth, its aura is almost tangible. To get a handle on Ngarrindjeri lore, it's worth starting at the Murray River settlement of Swan Reach, where amid the fragrance of spring blossoms and the sound of the breeze in the treetops, a ferry trundles lazily across the river. Back in 1936, Swan Reach became home to the Meru clan of the Ngarrindjeri, who were forcibly relocated from the South Australia-Victoria border. Just 15km further downriver from Swan Reach, what is today the Ngaut-Ngaut Conservation Reserve has for thousands of years been home to other Ngarrindjeri clans. The rock art of Ngaut-Ngaut was the first in Australia to be subject to archaeological investigation, and is still among the most intriguing. 'Believe it or not,' says my guide, Cynthia Hutchinson, pointing to a particularly striking example, 'that rock carving you can see is of an estuary dolphin. Thousands of years ago, sea dolphins used to migrate as far inland as here. Just goes to show how the water level has dropped since then.' The Ngaut-Ngaut Conservation Reserve is also a regular stopping point for the PS Proud Mary, a paddle steamer operating out of Blanchetown, 133km northeast of Adelaide. The Proud Mary's skipper, Captain Robert Stone, is an expert guide to the heritage of the lower Murray. 'This canoe tree would be several hundred years old,' he says, his arms spanning a giant river red gum. 'When the Ngarrindjeri people made canoes from the tree, they always preserved the spirit of the tree by a special method of cutting the bark that left the tree alive.' To the Ngarrindjeri, nature is a partner rather than something to be tamed. Matthew Rigney, the Ngarrindjeri chairman of the Murray Lower Darling Indigenous Nations group, likens the now-threatened Murray River system to a supermarket. 'It provides food, shelter, a spiritual connection and a cultural and social order,' he says. Further along the Coorong lagoon, part of the Murray wetland system, the Ngarrindjeri have set up the Coorong Wilderness Lodge. Managers George and Shirley Trevorrow take guests on walking and kayak tours, highlighting Ngarrindjeri culture and the environment. One chapter in Ngarrindjeri history came to a close in July with the return of remains that had been held at the University of Edinburgh since colonial days. Speaking at the ceremony, Ngarrindjeri tribal elder Tom Trevorrow says the remains could now be laid to rest in their homeland. 'Indigenous peoples have been waiting a long time for this process to take place,' he says. Trevorrow also has views on the problems facing the Murray River. 'The key to rescuing the Murray River is to reclaim the swamplands,' he says. 'These act as a natural filtering system. If the wetlands can be regenerated, then the whole river can be saved.'