On the 15th of December, 1845, Mitchell started from Buree with a very large company, including E.B.  Kennedy as second in command, and W. Stephenson as surgeon and collector.  He struck the Darling much higher than Fort Bourke, and it was not until he was across the river that he passed the outermost cattle-stations, which had sprung rapidly into existence since his last visit to the neighbourhood.  The Narran was then followed up until the Balonne was reached.  This river, in his superlative style, Mitchell pronounced to be the finest in Australia, with the exception of the Murray.  He then struck and followed the Culgoa upwards until it divided into two branches; he skirted the main one, which retained the name of the Balonne.  On the 12th of April he came to the natural bridge of rocks which he called St. George’s bridge, and which is the site of the present town of St. George.  Here a temporary camp was formed; Kennedy was left in charge to bring the main body on more slowly; Mitchell with a few men went ahead.  He followed up the Balonne to the Maranoa, but as the little he saw of that tributary did not tempt him to further investigation of it, he kept on his course up the main stream until he reached the junction of a stream which he named the Cogoon.  This riverlet led him on into a magnificent pastoral district, in the midst of which stood a solitary hill that he named Mount Abundance.  It is in his description of this region in his journal that we first find an allusion to the bottle tree.

The party wandered on over a low watershed and came down out on to a river which, from its direction and position, he surmised to be the Maranoa, the stream he had not followed.  At this new point it was full of deep reaches of water, and drained a tract of most pleasing land.  On its banks he determined to await Kennedy’s arrival.

Kennedy overtook him on the 1st of June, bringing from Sir Thomas’s son Roderick despatches which had reached the party after the leader’s departure.  Amongst other items of news in the despatches was the report of Leichhardt’s return, and of the hearty reception that he had been accorded in Sydney.  One piece of random information, a mere floating newspaper surmise, but enough to arouse Mitchell’s suspicious temper, annoyed him greatly.  “We understand,” it ran, “the intrepid Dr. Leichhardt is about to start another expedition to the Gulf, keeping to the westward of the coast ranges.”

As this seemed to indicate an intention of trespassing on Mitchell’s present field of operations, he naturally felt some resentment not likely to be allayed by such a paragraph as the following:  “Australia Felix and the discoveries of Sir Thomas Mitchell now dwindle into comparative insignificance.”