He rose rapidly in the civil service, becoming Assistant Surveyor-General by 1856 and the Surveyor General of South Australia in 1861. He is remembered today for Goyder's Line of rainfall, a line used in South Australia to demarcate land climatically suitable for arable farming from that suitable only for light grazing, and for the siting, planning and initial development of Darwin, the Northern Territory capital and principal population centre. However, Goyder was an avid researcher into the lands of South Australia (including the present-day Northern Territory) and made recommendations to a great number of settlers in the newly developing colony, especially to those exploiting the newly discovered mineral resources of the state.