There are over 200 lakes in the Southern Yorke Peninsula region. When pastoralists first took up their leases, the entire Peninsula was covered in mallee scrub. During winter and spring the lakes were fresh water lagoons, drying out in the hot summers.
When European settlers arrived, they set to work and cleared off the scrub, result the naturally occurring salt and minerals in the soils gradually leached into the low-lying lagoons with every winter's rainfall, then when the lakes dried out during summer the salt crust remained. By the time the drought of the 1880s arrived there was a reasonable crust of salt on most of the lakes, which farmers took to manual scraping, bagging and delivering to their local ports for delivery to Port Adelaide.
The Peninsula’s first known Salt Refining business was located on a lake just east of Yorketown. It was set up by a Frenchman named Tocchi who formed the SA Salt Refining Co about 1876. This locally produced salt was 15/- a ton cheaper than the imported product, and of equal quality. Production was about two tons a day, by an evaporation system using wood-fired boilers. The liquid solution was first being pumped from two 12,000 gallon holding tanks through a series of six long filters, and then into the boilers. The bagged salt was carted to Coobowie where it was stored in a beach side holding shed. It was carried by horse and dray out to ketches waiting in the shallow water for transportation to Port Adelaide. This became the Castle Salt Co, who had their refinery at Birkenhead (Port Adelaide). The storage shed at Coobowie was capable of holding 4,000 bags of bagged salt.
After some years the Castle Salt Co was reconstructed, and formed the Castle Salt Co-operative Co. Ltd, moved to Edithburgh. A new Refinery was built on cliff-top land south-west of and facing the jetty. Early in the 1900s two more salt refineries constructed factories: Commonwealth Salt Refining Co. Ltd, and The Standard Salt Co. Ltd.
Although strictly a seasonal operation, salt proved to be the lifeblood for many Southern Yorke Peninsula farmers and families. Production rose from a few thousand tons in the 1880s, to over 40,000 tons in the early 1900s. At the peak years to come production increased to nearly 60,000 tons per year, with nearly all refined and shipped from Edithburgh.
Lake Fowler (between Yorketown and Edithburgh) was the largest salt scraping enterprise. Along the southeast side of the lake a large hill of gypsum existed, measuring approximately a mile long (1.6 km) x 80 ft high x 350 ft wide. The SA Gypsum Co. Ltd was formed in 1898 to mine the gypsum and transport it to Edithburgh.