In 1922 an agreement was signed between the prime minister Billy Hughes, the acting premier for South Australia, John George Bice,[3] and the premier of Western Australia, James Mitchell to set the border along the 129th meridian eastlongitude and defined the boundary by lines drawn north and south through the centre of the Deakin Obelisk, erected in 1926 near Deakin, Western Australia and the Kimberley Obelisk, erected in 1927, near Argyle Downs, in the Kimberley Region of Western Australia.[1] In 1963, when the survey on the ground was continued, it was realised that there was no possibility of these lines meeting exactly at the 26th parallel south.[1]
In June 1968 two monuments were erected at the junction of the boundaries approximately 127 metres (417 ft) apart running east–west along the 26th parallel south. The most easterly monument common to all three jurisdictions was named Surveyor Generals Corner at the suggestion of the Director of National Mapping.[4] The site is not named after a single Surveyor-General, because there were a number of them present as follows.[1]
On 4th June 1968, two concrete pillars were completed to mark Surveyor-Generals Corner in the presence V.T. O'Brien, Acting Director of Lands, N.T., P.J. Wells, Acting Surveyor-General, N.T.; H.A. Bailey, Surveyor-General, S.A.; Harold Camm, Surveyor-General, W.A.; and B.M. Allwright, Surveyor, N.T.
Access
From 7 March 2003, access to the area was restricted following a decision by the Irrunytju (Wingellina) Community in whose traditional land the Surveyor Generals Corner is situated. Access to the area is limited to guided tours and visitors require a special permit in addition to the standard Great Central Road transit permit.[5]
The nearest settlement is the Aboriginal community of Kalka in South Australia, situated on the Gunbarrel Highway just a few kilometres to the south.
^"Border Lengths - States and Territories: Western Australia - South Australia - Northern Territory border". Geoscience Australia, Government of Australia. 2021. A glance at most maps of Australia will tell you something that isn't quite true. The border which runs along the eastern edge of Western Australia is not actually one continuous straight line. [...] The [1922] agreement set out the border as being a line determined by the 129th meridian east longitude. However, the agreement required that the boundary be defined by lines running north and south [...] and in June 1968 two monuments approximately 127 metres apart were erected at the junction of the boundaries.