He returned to Tasmania in 1854, and was appointed Inspecting Surveyor for the southern part of the island.
In response to an invitation from Augustus Charles Gregory, who was then Surveyor-General, he went to Queensland in 1861, and was appointed Staff Surveyor.
In December 1889, on the resignation of William Alcock Tully, Davidson exchanged this position for that of Surveyor-General.
[1] Davidson had the "Cliveden" homestead built for him on a bend of the Brisbane River in Oxley, Queensland in 1889.
[2] Media related to William Montgomery Davenport Davidson at Wikimedia Commons