[1] Having made a tidy profit of several thousand pounds from his second overlanding trip, the young Eyre (then only twenty-three years old) turned his attention to the interior, and the speculation surrounding the possibility of an inland sea.
Planning a three-month expedition to the head of the Spencer Gulf, he left Adelaide with five other men on May 1, 1839, taking two drays and travelling north for the coastal plain west of the Flinders Ranges.
On his return trip he turned east after leaving the Flinders behind and instead travelled back to Adelaide down the River Murray, reaching home on June 29.
They reached their farthest point some 50 km (31 mi) west of the modern site of Ceduna, forced back by lack of water.
[2] Eyre then led his party across country back to the head of Spencer Gulf and their old campsite at Depot Creek, visiting and naming the Gawler Ranges (for the Governor) on the way.
Baxter is assumed to have crossed the Willochra Plain, and after traveling some 100 km (62 mi), he had seen what he called nothing but a "low flat sea of scrub".