Crossing the Blue Mountains. Due to the rough terrain and lack of resources, the Blue Mountains were seen as an impassible barrier for future exploration from the time of Captain Cook’s landing in 1770 through to 1813. In 1813, Gregory Blaxland, William Charles Wentworth, and Lieutenant Lawson, along with four servants, four pack horses and five dogs, set off on an exploration which was to create history. On the 11th May 1813 the explorers departed from Emu Plains reaching the foothills of the Blue Mountains, or Glenbrook as it is known today. Just west of Katoomba you can see the remains of a Eucalyptus tree marked by the famous explorers Blaxland Wentworth and Lawson.