The marking of the Queensland-South Australian border was undertaken in 1879-1880 by the South Australian Government as the final section of a survey of its border on the 141st meridian, which had started at the Murray River. The surveyor chosen to undertake the border survey was William Barron, who had recently accompanied an expedition to South Australia's western districts. In May 1879 Barron, accompanied by a survey team with horses and camels, set out from Mulligan Springs, east of Mount Hopeless in north-east South Australia. After checking the border line north to the end of the completed survey at the 29th parallel (Fort Grey), he began working towards the 26th parallel. The work was difficult and tedious, involving trudging over sand ridges and claypans, and marking the line by mileposts recording the distance from the survey starting point at the Murray River. William Barron marked the border from Cameron Corner north to Cooper Creek, where his health failed and he was forced to return to Adelaide.