Marree is a town located in South Australia, a point of intersection between two routes, the Oodnadatta Track and the Birdsville Track.
My suggestion
If you're travelling by van, I suggest that you spend a night at Coward Springs before heading back to Marree. The shaded area is very pretty. You can also take a dip in a natural spa (full of sand)!
This part of Australia is unique and distinguishes itself from the other part of Queensland and the rest of the country by its impressive rain forests, deserted beaches, and very diverse animal and plant life. You must have heard people talk about the "wet tropics" which is home 36% of the country's animal species.