The rock carvings in Pekina Creek, Upper Wepowie Creek and Rock Hole were observed and recorded by Mr H. E. Burrows from the South Australian Museum in 1959. After the examination it was found that all three carvings were similar and most likely were done by the same tribe or group of people occupying this district. This tribe was said to be the Ngadjuri tribe as the carvings were well inside their boundaries. The rock carvings are said to be thousands of years old and their meaning somewhat obscure. One theory is that they represent the fertile areas of food.
The Goyder is a controversial line of demarcation between pastoral areas and the cereal-growing country. This was mapped out in 1865 by the Surveyor-General of South Australia - George Woodroffe Goyder.
Rendezvous of the Magpie
Upon the naming of the town, aboriginal names were said to be considered. Three names were sent in and Orroroo was eventually selected and the township was proclaimed. Over the years many discussions took place as what the name meant. Examples were such as 'wind in the trees' or 'dust, wind or any rapid movement'. One man Frank Warwick, of Holowiliena Station, was well versed in native lore, asserted that Orroroo meant 'the rendezvous of the magpie.'
On the 24th August 1923 the electric power house was declared open in Orroroo and the lights were switched on for the town. This was done by Cr Martin Redden, Chairman of the District Council, in the presence of one of the largest crowds in the history of Orroroo. The plant installed was secured from Kanowna in Western Australia and consisted of 230 voltage. The power house engines were shutdown on 4th July 1962 to change to AC power which gave the houses 240 voltage.