For 20 years from the time of first settlement at Sydney Cove, the Blue Mountains to the west of Sydney had seemed an impenetrable barrier to what lay beyond. Military expeditions, escaped convicts seeking a safe haven, and the mere curious nature of the free settlers had failed to guess or find what lay beyond.
The colony was experiencing problems as coastal pasture-lands were depleted by over grazing. Gregory Blaxland, a grazier frustrated with attempts to gain more land to accommodate his increasing flocks and herds, turned to exploration.
He presumed that by keeping to the divides between the creeks he might be able to travel more freely than his predecessors who had attempted to follow the river courses. To cross the mountains he determined, could best be achieved by climbing the plateau to the north of the Warragamba River and to proceed westward by keeping to the high ground.
On May 11th. 1813 he set out to cross the mountains. With him were William Lawson, another grazier, and William Wentworth, a twenty year old who had already been granted land to establish himself. A primary motivation of the 3 men and their party of servants, was the search for new pastures upon which to graze their livestock.
After a night at Emu Plains, near Penrith, they traversed the slopes on horseback to gain the high ground. Water and suitable fodder was scarce, and it became necessary to make expeditions into the gullies they planned to avoid. Travel was difficult, but not impossible, and they continued to follow their plan.
They often camped early and spent their afternoons cutting and preparing a path to follow the next day. Often the paths they prepared led to little or no progress and morale waned as they began to get frustrated and tired.
Late in the afternoon of May 27th. they reached Mount York from where they viewed a large area which seemed to be clear of trees, and assumed it to be swamp land. The following day the true nature of their discovery became apparent, for below them lay a vast plain of forest and grass. They descended, allowing their poorly conditioned horses to graze and water, and to rest before continuing.
They travelled west to explore the extent of the plain, turning back only when provisions were insufficient to continue. each received 1,000 acres of the newly discovered plains for their arduous and enterprising journey.
The Great Western Highway almost exactly follows the route they took and their names are attached to towns and features of the Blue Mountains National Park.