The Simpson Desert lies between Lake Eyre in the south, the Macdonnel Ranges in the north, the Mulligan and the Diamantina Rivers in the east, and the Macumba and Finke Rivers in the west. The first European entered the Simpson Desert in 1845. But the desert remained a mystery until Madigan made an aerial survey in 1929. He named the desert after Simpson, President of the South Australian Branch of the Royal Geographical Society of Australia.