He set out westwards for Portland on 13 October 1840 into what was uncharted and largely unknown territory. He crossed the Moorabool River north of Geelong near Buckley's Falls. Then proceeded to cross the Nuriwillum or Lea River. The use of aboriginal names for geographical features was a notable feature throughout his surveying career; European toponyms have superseded most of them. He then went north of Lake Corangamite and Lake Colac which he named and ascended Derrinallum or Mount Elephant twenty miles to the west on the 26th. Unable to directly go to Portland because of swampy country, he then continued northwest towards Gariwerd or the Grampians. On the 29th he ascended Dooroobdoorabul or Mount Shadwell and a day later Mount Rouse. Further thwarted by swampy land he headed north to Wiribcot or Mount Abrupt at the southern end of the Grampians which he ascended on 6 November. From here he was able to avoid difficult country by heading south and arrived at Portland on 14 November where he was accommodated and welcomed by Edward Henty.