Leichhardt arrived in New South Wales in 1842, and after some botanical excursions about the Hunter River district, he travelled overland to Moreton Bay, and there occupied himself with short expeditions in the neighbourhood, pursuing his favourite study of physical science. When the subject of the exploration of the north was mooted, he was desirous of securing the position of naturalist, but the delay in forming the projected expedition disappointed him, and he resolved to try and organise a private one. In this he received very little encouragement. He persevered, however, and eking out his own resources by means of private contributions, both in money and stock, he managed to get a party together. On the 1st of October, 1844, he left Jimbour station on the Darling Downs, on the trip that was destined to make his name as an explorer. His preparations were on a much smaller scale than Mitchell's. Considering the importance of the undertaking, his party was absurdly small. He had with him six white and two black men, seventeen horses, sixteen head of cattle and four kangaroo dogs; and his supply of provisions was equally meagre. His plan of starting from Moreton Bay to Port Essington differed considerably from Mitchell's proposed journey to the Gulf from Fort Bourke, but although longer and more roundabout, it would be a safer route for his little party to adopt, as they would keep to the comparatively well-watered coastal lands. Leaving the Condamine, he crossed the northern watershed, and struck the head of one of the main tributaries of the Fitzroy River, which he named the Dawson. Thence he passed westward into a region of fine pastoral country, which he named the Peak Downs. Here he named the minor waters of the Planet and the Comet, and Zamia Creek. On the 10th of January, 1845, he found the Mackenzie River, and thence crossed on to and named the Isaacs, a tributary of the Fitzroy coming from the north. This river they followed up till they crossed the watershed on to the head waters of the Suttor River. They followed this stream down until it brought them to the Burdekin, Leichhardt's most important discovery.